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ZRCC, Z80+RAM+CPLD+Compact Flash [message #7257] Mon, 16 March 2020 05:58 Go to next message
plasmo is currently offline  plasmo
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I like the idea of a low-cost Z80 running CP/M with minimum component count, but I don't like Z80 having to share the spot light with a processor many times its performance. So instead of using a powerful modern microcontroller as the I/O processor, I used a CPLD instead. The CPLD is Altera EPM7064S which is compatible with Atmel ATF1504. The CPLD's logic fabric can emulate a small ROM, 64 bytes, a simple serial port, and glue logic functions. The small ROM is enough to load program from the compact flash disk into RAM and execute. In case the compact flash is new and un-initialized, the ROM can also read in program from the serial port to initialize the new CF disk and load it with boot program. Beside the internal ROM, the CPLD also implemented a simple serial receiver and bit-bang serial transmitter. The serial receiver is just glorified shift register with fixed baud rate and protocol, 115200-N-8-1. The remaining CPLD is glue logic.

I name this simple computer ZRCC which stands for Z80+RAM+CPLD+CF which are the list of major components, i.e.,
* Z80 running at 22MHz
* 128K banked RAM, 512K optional
* EPM7064S CPLD
* Compact flash drive
* CP/M-ready
* 26-pin I/O expansion (RC2014-lite)
* Optional I2C bus
* 84mm x 51mm 2-layer pc board

There are two options depending on the programming of CPLD:
* 512K banked RAM. I hope to port RAM-only version of ROMWBW with that option
* I2C bus that can drive 128x64 OLED LED display and other I2C peripherals. I also found it is fast enough to drive RGB LED array based on WS2812B. The protocol is not I2C, just pulse width modulation, but that can be driven with bit-bang output. It'll be fun to have a LED light strip controller based on Z80.

PC board is out to JLCPCB yesterday.
Bill
/forum/index.php?t=getfile&id=1691&private=0

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7274 is a reply to message #7257] Tue, 17 March 2020 11:09 Go to previous messageGo to next message
cmacarthur is currently offline  cmacarthur
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Looks GREAT
Have you considered using the BQ4017MC-70 ?
OR
Is 2MB to much NV-RAM for CP/M?
CM

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7280 is a reply to message #7274] Tue, 17 March 2020 17:43 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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It makes for nice RAM disk, but fairly expensive. I'm looking for $10 Z80 CP/M kit, but I'm not there yet.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7281 is a reply to message #7280] Tue, 17 March 2020 17:50 Go to previous messageGo to next message
cmacarthur is currently offline  cmacarthur
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I missed the $10 part....

FYI
With the COVID-19 travel restrictions, I have not been able to pickup the package you sent or my shipments from jlcpcb etc...

So I have been keeping busy stripping old boards...
(I can't call it a day until I burn my fingers. So with nothing to solder, I just have to burn them on the heat gun)

As soon as I can, I will be sending you a package of parts...
How many pounds of LEDs can you use?(LOL)

CM

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7284 is a reply to message #7281] Tue, 17 March 2020 18:48 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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I saw your note about new rule for self quarantine for 2 weeks. I remember reading a story about people in Wuhan, China left for work in the morning, but not allow to return home that night. It's happening in North America now.

The $10 CP/M Z80 kit is a goal I'm striving for. I can do $15, but $10 is hard even with used Z80 and CF disk.

You can't overwhelm me with LEDs, because I'm already overwhelmed with LEDs! 20+ years ago I had this crazy idea that we can illuminate houses with LED, that I can grow healthy plants with blue LED so I bought reels upon reels of white/blue/red LEDs to experiment. Shouldn't have bothered; the LED technology left me in the dust. I do have a wonderful collection of LED light bulbs/spotlights over a span of 20 years, some of them were quite expensive at the time.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7344 is a reply to message #7284] Sat, 28 March 2020 09:14 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
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Nice - is there room in the CPLD for a timer interrupt or not ?

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7348 is a reply to message #7344] Sat, 28 March 2020 12:12 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Depending on board configuration. There are two discrete pins that can either be memory bank selects for a 512K RAM or used as bit-bang lines for I2C. As bit bang lines, it can control an I2C RTC such as PCF8563 which can generate periodic interrupt, but in that case the banked RAM is only 128K.

This is what it looks like at this moment. Something wacky about it--it works really well when I have an oscilloscope hooked up, but stop working when I remove the scope. Maybe the design is so close to the limit that Heindenberg Uncertainty Principle applies? Rolling Eyes Laughing
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7368 is a reply to message #7348] Mon, 30 March 2020 08:00 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
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Either i2c or RAM or can it be both providing you are careful to do i2c from common memory space so the fact the address pins are bouncing around doesn't matter ?

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7372 is a reply to message #7368] Mon, 30 March 2020 11:51 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Yes, that may work except when bank registers are wiggling, it can issue I2c commands inadvertently. The chance of a meaningful command is pretty low, however.

Right now I'm struggling to find two more gates for banked 512K RAM configuration. Everything does fit for banked 128K RAM plus bitbang I2C.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7426 is a reply to message #7372] Sat, 04 April 2020 07:28 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Giving up on current design having 512K banked memory capability. I simply don't have enough logic in the EPM7064S. I'll have to add an external OR gate (74LS32) to have that capability.

Now the 512K RAM option is off the table, I ported CP/M2.2 and it is working well. Power consumption is about 150mA running CP/M. Created a homepage for ZRCC here:
https://www.retrobrewcomputers.org/doku.php?id=builderpages: plasmo:zrcc

The design is quite simple and easy to assemble yet with 22MHz CPU clock, it is one of the fastest Z80 with CP/M. Still unable to reach the $10 break even price for kit, but $15 is do-able. I plan to offer limited ZRCC kits for $20 just to give me some margin for cost overrun.

Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7436 is a reply to message #7426] Mon, 06 April 2020 14:15 Go to previous messageGo to next message
greghol is currently offline  greghol
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Bill,

Could you dead bug bug a '32 to get it working and then make that an option for the builder? I think I have single gate SMT devices laying around here too.

Greg

plasmo wrote on Sat, 04 April 2020 07:28
Giving up on current design having 512K banked memory capability. I simply don't have enough logic in the EPM7064S. I'll have to add an external OR gate (74LS32) to have that capability.

Now the 512K RAM option is off the table, I ported CP/M2.2 and it is working well. Power consumption is about 150mA running CP/M. Created a homepage for ZRCC here:

The design is quite simple and easy to assemble yet with 22MHz CPU clock, it is one of the fastest Z80 with CP/M. Still unable to reach the $10 break even price for kit, but $15 is do-able. I plan to offer limited ZRCC kits for $20 just to give me some margin for cost overrun.

Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7438 is a reply to message #7436] Mon, 06 April 2020 15:33 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Built up all 5 ZRCC to check out the design. 4 boards work right away, the 5th board gave me considerable trouble, but eventually I found the problem (it was a faulty pc board!Wink and it is now working as well. CP/M2.2 is ported as well as Steve Cousin's SCMonitor. Working on porting CP/M 3 to it.

There are a total of 205 solder joints so it averages about 30 minutes to assemble, clean up, populate, and power up a board.

I'll sit down this week to finalize ZRCC design. I need to trim 1mm off the width of the pc board so it can be 50mm x XXmm where XX is 100mm or less. This way each 100x100mm pc board contains two ZRCC pc boards, this is a cost saving measure.

Per Greg's request, I will also design ZRCC2 that includes a 74LS32 so it can support 512K RAM as well as I2C bus.

Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7440 is a reply to message #7438] Mon, 06 April 2020 16:01 Go to previous messageGo to next message
mikemac is currently offline  mikemac
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Out of curiosity, what was wrong with the one PC board and what did you have to do to fix it? Just for my own education in case I ever produce more than a single board for any design.


Mike

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7446 is a reply to message #7440] Mon, 06 April 2020 19:46 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Mike,
Normally JLCPCB produces high quality pc boards, but they goofed this time. The boards were fabricated right after the factory had started up from the COVID-19 shutdown. It looks like a streak of excess chemical has over-etched the pc board and cut two traces. It is localize to just one board and one narrow band as if a drop of acid was splashed on it. Their electrical testing should've caught this problem, but did not. I recall the board fabrication process was slow and spent quite a bit time waiting on the electrical testing. Maybe there was some problems with the testers.

Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7448 is a reply to message #7446] Mon, 06 April 2020 20:43 Go to previous messageGo to next message
wsm is currently offline  wsm
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As a follow-on to PCB issues, I've encountered two issues with the many dozens of boards I've received.

1) One board in a batch from ITEAD that was over etched. A .008" trace disappeared for over an inch and nearby traces appeared to have been narrowed.

2) A whisker between two traces on a board from AP Circuits. This could not be seen under magnification with bright light and was only identified after narrowing the area to about 1/4" and running an Xacto blade between the two traces.

Overall I think we're getting great value on PCBs that now only cost a fraction of what they used to cost. That being said, I do question the quality of the electrical testing during fabrication and now choose to view all my boards under magnification before adding any components. Luckily, I haven't seen any problems with my orders from PCBWay, including some with .006" traces and spacing.

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7574 is a reply to message #7448] Tue, 28 April 2020 19:16 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Received two ZRCC designs from Seeed Studio. Seeed production is considerably slower than JLCPCB, it took over 2 weeks to get the boards vs 5 days for JLCPCB post COVID-19. The quality of pc boards are wonderful as usual for both JLCPCB and Seeed, except they weren't able to read my mind and fix my design mistakes! The ZRCC rev1 had two signals swapped; a couple cuts and jumpers are required to make it work. CP/M2.2 and CP/M3 are ported successfully. I even have a version of Steve Cousin's SCMonitor with Startrek program pre-loaded so I can boot and start playing Startrek immediately.
/forum/index.php?t=getfile&id=1775&private=0

ZRCC2 is the 512K RAM version of ZRCC where an external 74LS32 is needed to augment the overflowing CPLD logic. The board is slightly larger than ZRCC. It SEEMS to work, but I need spend more time before I know for sure. This is the hardware I want to port RomWBW to.
/forum/index.php?t=getfile&id=1776&private=0

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7575 is a reply to message #7574] Tue, 28 April 2020 19:28 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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I describe the process of bootstrap a newly assembled ZRCC here:
https://www.retrobrewcomputers.org/doku.php?id=builderpages: plasmo:zrcc:zrcc1:cf_installation

It is a rather involved process that starts with loading of serial bootstrap through the serial port and then load utility software to program the new CF disk and then the process of uploading various CP/M software into the new CF disk. I want to highlight a Youtube video I made to show a TeraTerm macro executing the bootstrap process in 65 seconds. It should give you a feeling about the speed of ZRCC.

https://youtu.be/eARz73N0KL0

Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7582 is a reply to message #7575] Thu, 30 April 2020 22:19 Go to previous messageGo to next message
frax is currently offline  frax
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Looks beautiful as usual. Now please integrate the USB dongle onto the PCB so I can just plug the cable in directly Smile
I realize this would totaly not be within your $10 goal but it could be optional?

--frax

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7583 is a reply to message #7582] Fri, 01 May 2020 04:23 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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The CP2102 USB adapter is very inexpensive, around $2 in quantity of one (shipping included), so it is cheaper to just purchase the adapter board and solder it down. The power consumption of ZRCC is low enough that it can be powered directly by the USB serial adapter. I should try it. Thanks for the suggestion.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7586 is a reply to message #7583] Fri, 01 May 2020 07:53 Go to previous messageGo to next message
frax is currently offline  frax
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I realize that, but integrated would look so much better Smile And easier to fit in a case.

--frax

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7589 is a reply to message #7586] Fri, 01 May 2020 11:06 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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I will have to look into USB-to-serial chip to see whether there are DIP package available. So far ZRCC is designed with through hole components to encourage hobbyists to build it themselves.

As for enclosure, the board is smaller than Zuno ( https://www.retrobrewcomputers.org/doku.php?id=builderpages: plasmo:zuno), so it should fit within the ATMega enclosure by redesigning the power jack and location of the USB-serial adapter.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7590 is a reply to message #7589] Fri, 01 May 2020 19:31 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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A video of ZRCC as WS2812B controller driving a 5x10 panel of RGB LED. There is one data bit in an I/O register in ZRCC that drives a status LED. The 22MHz Z80 is fast enough to bit bang the I/O register to generate pulse train of different width correspond to binary 0 and 1. Each RGB LED has a red, green, and blue LED, each driven with 8 bits of intensity value. 24 pulses are consumed by each RGB LED and the remaining pulses are passed along to next RGB LED. The 5x10 panel of RGB LED is around $6.

https://youtu.be/18sMIV1OR7g

Bill

PS, the color are quite brilliant, but my camera is unable to capture it.

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7592 is a reply to message #7590] Sat, 02 May 2020 05:59 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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I forgot that I had made a pc board for the RGB LED panel for another project. It plugs in to ZRCC. I took a still photo and turn down the exposure to get better color representation of the RGB LED.
Bill
/forum/index.php?t=getfile&id=1777&private=0
/forum/index.php?t=getfile&id=1778&private=0

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icon14.gif  Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7593 is a reply to message #7592] Sat, 02 May 2020 08:20 Go to previous messageGo to next message
cmacarthur is currently offline  cmacarthur
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You build the BEST TOYS!!!

CM

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7604 is a reply to message #7426] Tue, 05 May 2020 20:21 Go to previous messageGo to next message
djmartins is currently offline  djmartins
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plasmo wrote on Sat, 04 April 2020 10:28
The design is quite simple and easy to assemble yet with 22MHz CPU clock, it is one of the fastest Z80 with CP/M. Still unable to reach the $10 break even price for kit, but $15 is do-able. I plan to offer limited ZRCC kits for $20 just to give me some margin for cost overrun.

Bill
A 22Mhz Z80 CP/M computer kit for $20?
TAKE MY MONEY BILL!

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7605 is a reply to message #7604] Tue, 05 May 2020 20:52 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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I'm waiting for rev 1.1 pc board to show up, and I'm also waiting for CF adapters before I can offer the $20 kit. They should all be here this week. There is an additional $5 shipping charge for buyers in USA. International shipping is $15. Picture below shows what a completed kit will look like. The "no brand" CF disk is 64 meg capacity. It is already loaded with software. Documentation for rev1/rev1.1 board is here:

https://www.retrobrewcomputers.org/doku.php?id=builderpages: plasmo:zrcc:zrcc1

Bill

Edit, I'll put you down as an interested buyer.
/forum/index.php?t=getfile&id=1783&private=0

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7606 is a reply to message #7605] Tue, 05 May 2020 21:01 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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$5 shipping in USA is reasonable, but $15 international shipping is terrible! Especially since the kit is only $20. Since the design is fully released, I would encourage hobbyists outside of USA to just order the pc boards and parts and build ZRCC themselves. If you've ordered surplus pc boards and extra parts enough to build 10 boards, please feel free to sell off your extra at whatever price you felt is reasonable. I don't care if you sell the same kit for $40 or whatever.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7607 is a reply to message #7605] Tue, 05 May 2020 22:25 Go to previous messageGo to next message
djmartins is currently offline  djmartins
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plasmo wrote on Tue, 05 May 2020 23:52
Edit, I'll put you down as an interested buyer.
I am and thanks.

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7608 is a reply to message #7607] Wed, 06 May 2020 05:07 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
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A couple of questions on the docs

1. "The CF bootloader, in turn, loads 3K bytes worth of data located in track 0, sector 0xF0 to 0xF6 of a CF disk into 0xB400" but the code appears to use F8-FD
2. The four memory page settings, one is "don't use". Does that 32K not work or is that a hangover from the older CPLD based system where that was the battery backed boots code ?

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7609 is a reply to message #7608] Wed, 06 May 2020 05:51 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Thank you for looking over the document carefully.
1. I have correct the document to read: "The CF bootloader, in turn, loads 3K bytes worth of data located in track 0, sector 0xF8 to 0xFD of a CF disk into 0xB400"

2. There are indeed 4 usable 32K pages. The high 32K of Z80 memory space always maps to highest 32K page of the 128K RAM, the low 32K of Z80 can map to any of the four 32K pages of the 128K RAM. The 32K page reserved for battery-backed boot code of Z80SBC64 design is now available for other applications.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7610 is a reply to message #7608] Wed, 06 May 2020 06:11 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
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Also some bugs I think looking over the code

- in cfbootloader you set LBA3 to 0x40. That will break on some drives. The correct values for LBA3 at 0xE0 (master) and 0xF0 (slave). The other bits are sort of historical (encoding, sector size) but not every old device ignores them entirely.

- In the cfbootloader properly you should wait for drdy after writing the drive select/LBA mode. As you don't change drive I think that doesn't matter

Also if you need more room

in a,(foo)
and 80h
jp nz,

could easily be

in a,(foo)
rla ; or some people prefer add a
jr c,

etc (rra for low bit test)

You can make the CPLD a lot shorter (aside from simple optimizations like rla/rra for tests) because the ATA standard says that on power on or hardware reset

g) .... In either case the device shall set the Sector Count register to 01h, the Sector Number register to 01h, the Cylinder Low register to 00h, the Cylinder High register to 00h, and the Device/Head register to 00h. Device 0 shall store whether or not Device 1 was detected in step d) because this information is need in order to process any Software reset or EXECUTE DEVICE DIAGNOSTIC command later;
h) Device 0 posts diagnostic results to bits 6-0 of the Error Register;
i) Device 0 clears the BSY bit when ready to accept commands that do not require the DRDY bit to be equal
to 1. Device 0 shall clear the BSY bit no later than 31 seconds from the time that RESET- is negated;
j) Device 0 sets the DRDY bit when ready to accept any command."

I'd never really thought about that until today but that might save you a bit of room on the CPLD as you just need to wait for DRDY issue the read command, wait for DRQ inir dec h, jp (hl)

Oh yes - and barring the details on the memory page setting the emulator should now support zrcc - I've booted it to the monitor, ot yet assembled a CF card image with CP/M.

Alan

[Updated on: Wed, 06 May 2020 06:12]

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7611 is a reply to message #7610] Wed, 06 May 2020 06:57 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Thanks for suggesting 0xE0 for LBA3. I've vacillated between 0x40 and 0xE0, I will stick with 0xE0 now.

I remember you've mentioned the trick
in a,(Wink
rla
jr c

I didn't use it because I know I'll just get confused later. (A few times during design reviews I've cursed the crazy programmer for writing obscure codes and only have someone pointed out that the crazy programmer was me!Wink

The default values for CF is useful. I have wanted a longer wait from power reset to boot from CF disk to give the user more time to pick the serial bootstrap mode. This may free up enough code space to put in a delay loop.

I'm thinking of multiple ZRCC or Z280 that uses the serial bootstrap to load common code at power up and reuse the CF interface for fast I/O interface. An intelligent console can serially poll each processor for status and issue command to a particular processor. A simulator would really help figuring out what everyone is doing.

Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7612 is a reply to message #7611] Wed, 06 May 2020 07:17 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
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You could do that sort of anyway - right now you check for a char then loop for CF drdy. If you looped through both at that point you'd get that for free.

Alan

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7628 is a reply to message #7612] Mon, 11 May 2020 16:46 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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I received the rev1.1 pc board of ZRCC. Everything checked out OK. The design files are released here:
https://www.retrobrewcomputers.org/doku.php?id=builderpages: plasmo:zrcc:zrcc1_1

I am working off backlog of buyers who have pre-ordered. If I have boards/kits/assembled boards remain, I'll post them on the RBC Wiki Single Board Computers page.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7669 is a reply to message #7628] Mon, 18 May 2020 21:39 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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I do have ZRCC kit as well as assembled/tested boards available. I've posted them on RBC Wiki Single Board Computer page. Kit is $20; assembled & tested is $45. Shipping is $5 in USA. I'm not shipping International right now because it is exceedingly slow.
Bill

[Updated on: Sun, 24 May 2020 05:15]

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7689 is a reply to message #7669] Sat, 23 May 2020 14:08 Go to previous messageGo to next message
djmartins is currently offline  djmartins
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Registered: February 2018
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This is a nice little machine!
Silly question but how can I add more drives to the compact flash or say setup a new 128Mb card with CP/M 2.2 and CP/M 3 with
a lot more drive letters than just A to D and then transfer files to them?
Reading the instruction for a new card it looks like it only installs the ZRCC monitor and CP/M 2.2 and I don't see how to add drives beyond D:.
I have a 9" LCD screen and someday will build a sorta portable CP/M machine with it but it will be a lot smaller than the
luggables of way back but will try to style it in that era and this board would be a great mainboard for that!

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7691 is a reply to message #7689] Sat, 23 May 2020 20:08 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Registered: March 2017
Location: New Mexico, USA
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In instruction on New CF, I added an updated Teraterm macro that will install CP/M2.2, CP/M3, HiTech C, and Zork. It will also install a special edition of SCMonitor with Startrek BASIC game pre-loaded. This the link: https://www.retrobrewcomputers.org/lib/exe/fetch.php?media=b uilderpages:plasmo:zrcc:zrcc1:zrcc_install_all.zip

To add more drives, the CP/M BIOS needs to be changed. For CP/M2.2, it will diminish the available TPA with more drives. For CP/M 3, that's not a problem. ROMWBW has a dynamic way to assign drives which is much better way of adding more drives. I'm not there, yet.

I'm interested in your LCD work. I have designed a board based on ZRCC idea, but the Z80 is dedicated as the LCD controller for a 5.2" monochrome LCD panel, UG-32F01. Home page is here, I'll update it now with the latest picture. https://www.retrobrewcomputers.org/doku.php?id=builderpages: plasmo:z80lcd

Bill

Edit, add picture of Z80LCD, Z80 controller for UG32F01
/forum/index.php?t=getfile&id=1798&private=0

[Updated on: Sun, 24 May 2020 05:17]

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7694 is a reply to message #7691] Sun, 24 May 2020 08:44 Go to previous messageGo to next message
djmartins is currently offline  djmartins
Messages: 40
Registered: February 2018
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Oh, I was just going to use a terminal board to connect a LCD to it, either the pi zero non w terminal or
the just4fun uTerm.
Nothing as complicated as what you've done there.
Basically gonna take a CP/M SBC, add a car LCD and a terminal board and battery charger/battery and throw it in a 3d printed case
or wooden case.
Bring out the CF card, power socket, and a power switch.
I take it ROMWBW takes a lot of work to get going on a new board?

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7695 is a reply to message #7694] Sun, 24 May 2020 11:26 Go to previous messageGo to next message
plasmo is currently offline  plasmo
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Registered: March 2017
Location: New Mexico, USA
Senior Member
I have not delved into the innards of ROMWBW. In the past, I designed the hardware to what ROMWBW expects rather than change ROMWBW to fit my hardware, so currently I don't have real understanding of ROMWBW.

What I'll do in the near term is change CPM3 BIOS to have 8 8-meg drives. That won't have any impact on TPA and is fairly easy to do.
Bill

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Re: ZRCC, Z80+RAM+CPLD+Compact Flash [message #7697 is a reply to message #7695] Sun, 24 May 2020 15:34 Go to previous messageGo to previous message
djmartins is currently offline  djmartins
Messages: 40
Registered: February 2018
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That sounds great.
I looked at the free space on the tiny little 8 meg drives and found that they are mostly EMPTY.
I forgot how 8mb used to be a lot and I used to install 10 and 20 meg drives in new 8086 machines
and installed DOS on them.
I did look at the .ttl files to see how it was setup and have a better understanding than when I posted.
The D: drive with 3 Zorks still has over 7Mbs left.
Now you need like 15 GIGAbytes for Windows 10.....
If I use the raspberry pi terminal I can use a usb keyboard and a hdmi LCD screen so while those are not at all retro
these days they are easily sourced and work well.
I just scored two King Kludge RK61 keyboards at a discount place and have $10 into the pair.
They are a white 60% keyboard with nice RGB backlighting and red mechanical switches though I would have preferred blues.
I suppose with 8 drives ROMWBW isn't as needed and I do prefer to use (learn) CP/M Plus.
So there is enough space on a 64Mb compact flash card for four more 8 meg drives?
Slap some more text adventures, FORTH, word processor, and some other junk and be good to go.

[Updated on: Sun, 24 May 2020 15:35]

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