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A New Small Z180 Board at 33MMHz [message #5111] Mon, 03 September 2018 14:27 Go to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
Along the lines of the various "Tiny" (credit to Plasmo) boards, I've designed and tested a small Z180 board which runs CP/M. Basic details are:

- Z8S180 at 33MHz
- 512KB SRAM for code + 440KB RAMdisk (zero wait states)
- 512KB Flash for code + 496KB "disk" (one wait state)
- Two TTL, RS-232 or USB serial ports
- A daughter I/O board with hex LEDs, DIP switch, RTC, 8MB flash and SD card is in the works

There are more details <here> as I haven't gotten around to developing a Wiki page. Schematics are <here> for the TTL/RS-232 version, <here> for the USB version and <here> for the I/O board.

The V1.0 processor boards work okay as-is with either DIP RAM or without I/O expansion headers. I made a mistake (I'll admit it) and used the smaller machine-pin holes for the I/O expansion headers rather than the more common square post headers. However, modified headers (square edges rounded) will work and V1.1 boards will have the larger square post holes.

There is a limitation to the CTS/RTS flow control on ASCI 1 when using a Z8S180 or Z8L180 processor due to a Zilog errata. When using flow control, CTS from a host works as expected but RTS to the host must always be enabled which can be accomplished via a simple board modification. V1.1 boards will properly support CTS/RTS flow control on ASCI 1 regardless of processor. RTS/CTS on ASCI 0 works properly and is not affected by the Zilog errata.

Full kits will be $45US including Canada/US shipping but excluding a +5V power supply for non-USB boards. Full M80 source for the BIOS and CP/M is available.

I currently have some extra V1.0 bare boards available for $10US including shipping. A pre-programmed 45ns flash chip is an extra $5.

Let me know if anyone is interested in one of these boards or kits. I'll need to know:

- TTL/RS-232 or USB-only board and bare board versus full kit?
- Is a V1.0 board or kit (with modified headers) acceptable?
- For the TTL/RS-232 board kit, do you want the four SMD devices pre-soldered at no cost?
- For the USB board kit, do you want the 13 SMD devices pre-soldered ($20 extra)?
- Would you prefer a fully assembled and tested board?

At this time I'm primarily wanting to know if there's any interest in these boards or kits. I'm waiting for a shipment of additional processors (only one extra on hand) so full kits won't be available for a couple of weeks. Only three TTL/RS232 and four USB-only full kits (V1.0) will be available initially and V1.1 board/kit availability will depend upon demand.

For those that may want a much more flexible Z180 development system, I do have some pre-assembled and tested NYOZ base modules. There's some verbose documentation <here> that definitely needs paring down.

Bill
Re: A New Small Z180 Board at 33MMHz [message #5112 is a reply to message #5111] Mon, 03 September 2018 14:36 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
First up I need to learn how to type and read ... I think we'd all love to have a processor at 33M MHz Smile
Re: A New Small Z180 Board at 33MMHz [message #5113 is a reply to message #5111] Tue, 04 September 2018 01:13 Go to previous messageGo to next message
pbirkel is currently offline  pbirkel
Messages: 60
Registered: October 2015
Member
Bill;

I'm interested in the TTL/RS-232 full kit, four SMD devices pre-soldered, modified-headers acceptable. What is your plan for availability of the I/O Demo Board?

paul
Re: A New Small Z180 Board at 33MMHz [message #5114 is a reply to message #5111] Tue, 04 September 2018 01:50 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
Messages: 265
Registered: November 2017
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So many new projects! Smile

Such slow shipping from China Sad
Re: A New Small Z180 Board at 33MMHz [message #5116 is a reply to message #5111] Tue, 04 September 2018 05:54 Go to previous messageGo to next message
just4fun is currently offline  just4fun
Messages: 126
Registered: May 2017
Location: Dark side of the Moon
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Hi,
do you know if HD64180RCP6X have the same ASCI 1 bug of the Z8S180 or Z8L180 (I haven't found any info on the HD64180 datasheet...)?

Re: A New Small Z180 Board at 33MMHz [message #5117 is a reply to message #5113] Tue, 04 September 2018 06:34 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
pbirkel wrote on Tue, 04 September 2018 01:13
Bill;
I'm interested in the TTL/RS-232 full kit, four SMD devices pre-soldered, modified-headers acceptable. What is your plan for availability of the I/O Demo Board?

Paul: Your name is now on one of the TTL/RS232 full kits.

I have the I/O Demo PCBs inhand but delayed the prototype testing until after I tested the base boards and BIOS. Additional BIOS development for the I/O board is still required. Realistically, it will probably be the end of the month before I'm ready to ship them and I'm mostly concerned with getting the CPLD FULLY tested since most builders probably don't have the tools to reprogram them.

re: Slow China shipping. I've had mixed results from 2 weeks to 2+ months. UTSource has been 2-3 weeks on previous orders and a lot of the delay has often been Customs. I normally use Digi-Key, Mouser etc. for low quantity testing and only use select Chinese suppliers due to availability or pricing on more expensive ICs.
Re: A New Small Z180 Board at 33MMHz [message #5118 is a reply to message #5116] Tue, 04 September 2018 06:56 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
Quote:
do you know if HD64180RCP6X have the same ASCI 1 bug of the Z8S180 or Z8L180

So far as I've read and tested, the significant errata are only on the Z8S* and Z8L* devices and are not on the Z80180 which was derived from the HD64180. Although it was a long time ago, I did build a few systems with the HD64180 and didn't run into any undocumented issues.

The significant Z8S and Z8L errata from a programmer perspective:
- CSI/O timing change and TXS reverting to high after the last bit
- CNTLB1 does not reflect the state of the CTS1 pin
- ASCI overruns stop all receives until the ERF bit is reset, regardless of data reads
Re: A New Small Z180 Board at 33MMHz [message #5119 is a reply to message #5118] Tue, 04 September 2018 13:33 Go to previous messageGo to next message
just4fun is currently offline  just4fun
Messages: 126
Registered: May 2017
Location: Dark side of the Moon
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Thanks for the info!
Re: A New Small Z180 Board at 33MMHz [message #5219 is a reply to message #5119] Sat, 22 September 2018 09:18 Go to previous messageGo to next message
gkaufman is currently offline  gkaufman
Messages: 137
Registered: October 2015
Senior Member
Bill -

Kit arrived quickly and went together easily - thanks for the very well written construction notes!
This is super-slick and tiny. Anyone looking for a small and fast CP/M system should build one up.

Looking forward to the IO Demo board as well.

- Gary

Re: A New Small Z180 Board at 33MMHz [message #5220 is a reply to message #5219] Sat, 22 September 2018 10:41 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
Gary,

Glad to hear that the kit arrived safely and went together without problems. I appreciate the followup and compliment.

The I/O demo board is progressing ... CPLD code has been written as has the BIOS disk support for the 8MB flash TSOP . Clock code from an existing similar project needs to be integrated. Initial BIOS release will probably only have drivers for the optional SD card and serial memory chip. I'll keep you informed.

I'm still waiting for my order with additional processors. It's now about four weeks and I expect them at any time.
Re: A New Small Z180 Board at 33MMHz [message #5395 is a reply to message #5220] Sat, 27 October 2018 09:44 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
My order of parts from UTSource finally arrived after 9 weeks rather than my previous experience of 2-3 weeks. I have all the parts for another RS232/TTL board and several USB boards per the first post in this thread.

The prototype I/O board has been assembled but testing has been delayed. I chose to try fight City Hall and the results were as expected Sad I'm ready to get back to testing the I/O board in the next few days.

The V1.1 upgrade has been layed out but I don't plan to order the boards and build/test a prototype unless I receive multiple requests for them. The V1.0 boards work fine for me.

Let me know if anyone wants one of these kits.

Bill
Re: A New Small Z180 Board at 33MMHz [message #5906 is a reply to message #5395] Fri, 01 February 2019 14:11 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
Status update:

V1.1 of the RS232/TTL and USB boards have been received and tested. There are two main changes:
1) The header holes were increased in size for typical headers.
2) A flip-flop was added to latch the TXS (RTS1) signal due to Zilog's CSI/O change (i.e. errata) in the Z8S180 and Z8L180 chips.

The I/O demo board was changed to IO2 and appears to be working okay. The main changes are:
1) The serial memory device was removed due to space constraints.
2) A Schmitt buffer was added on the slow-rising open drain clock interrupt signal.
3) Discrete pullups were added on the SD signal lines since the CPLD pullups can't be used.
4) An oscillator was added so the CPLD can clock the bits within an SD data byte from a single I/O operation rather than the CPU having to do multiple I/O operations per bit (i.e. bit-banging the data and clock). This results in a significant performance improvement and with a 33MHz processor the transfer rate is about 1.85MB/sec.

No BIOS changes are required for the upgraded base boards, however the BIOS has been upgraded to V2.0 and tested for use with the additional I/O board devices. The I/O demo board incorporates an 8MB flash disk and the SD card supports an 8MB disk with the rest of the card still useable as FAT32.

Send me a PM if you're interested in a full kit or just a PCB for any of these boards. Per the first post, base module boards are $10US and full kits are $45US including shipping. I also have one assembled and tested board of each type that I'll sell at the same price.

The IO2 boards are $15 which includes an installed voltage regulator and programmed CPLD. A full kit (excluding [H]TIL-311 displays) is $35US but will require fine-pitch SMD soldering. As time permits, I'll be fully assembling and testing a few of these I/O boards and making them available for a minimal surcharge.

http://www3.telus.net/public/wsm/MinZ-Both.jpg
Re: A New Small Z180 Board at 33MMHz [message #5958 is a reply to message #5906] Sun, 17 February 2019 13:51 Go to previous messageGo to next message
gkaufman is currently offline  gkaufman
Messages: 137
Registered: October 2015
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IO2 board received and hooked up, works very nicely and really slick!
Re: A New Small Z180 Board at 33MMHz [message #5963 is a reply to message #5958] Mon, 18 February 2019 09:09 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
Gary: Glad to hear it's up and running! I agree that these are neat little CP/M systems and quite speedy. Program loads are essentially instantaneous to the user and ASCIIART runs in just under 30 seconds.

My latest brain teaser is to see if I can make this a truly "TINY" encased system. The goal is to try make a single two-layer PCB inside a case that's 50x50x15mm or roughly 2"x2"x0.6". Mostly SMD components with similar basic specs: USB for power and serial I/O, 33MHz (I may try overclocking to 36.864), 512KB SRAM (optional piggy-back to 1MB), 512KB flash boot/disk, SD card and RTC. PCB layout is about 3/4 done.

The 8MB TSOP flash on the IO2 board is nice to have for resident bulk storage and reads via DMA are very fast. However, slow writes show the shortcomings of parallel NOR flash and why I'm not including it in a TINY system. If I were re-working the IO2 board, I'd probably substitute two serial quad I/O NOR flash chips making a byte-wide interface. Reads would add a BIT of overhead for setup but write programming would be in 256-byte pages rather than word-wide i.e. the programming delay reduced by a factor of 128.

The things some of us do when weathering a deep freeze ... Smile CP/M-3 and FAT32 support are on the possible "to-do" list as is banking more of the BIOS to go back to a 64K system instead of 63K.
Re: A New Small Z180 Board at 33MMHz [message #6562 is a reply to message #5963] Sat, 21 September 2019 11:40 Go to previous messageGo to next message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
Following along on the "Tiny" MinZ series, I developed a cased version of it. This version is small enough that it can be hung off a PC's front USB connector using an integrated USB-A to male Mini-B adapter.

Size: 50mm x 50mm x 15mm or roughly 2" x 2" x 0.6" (Hammond 1551S case)

Features:
- USB powered
- Z8S180 at 33.333MHz or over-clocked at 36.864MHz
- 512KB Flash - 1 wait state : Boot code + 496KB flash disk
- 512KB or 1MB SRAM - 0 waits : 436KB or 948KB RAMdisk
- 256 Bytes of EEPROM
- 64 Bytes of battery backed SRAM
- Two USB serial ports with RTS/CTS handshaking at 115,200 baud
- Micro SD card with 25 MHz SPI interface
- Real Time Clock with rechargeable battery backup (~4+ months)
- A RUN (green) / HALT (red) indicator LED
- One user programmable LED
- A RESET pushbutton

The current BIOS and software is for CP/M 2.2, all of which is embedded in flash. The SD card currently supports a single 8MB CP/M partition while also retaining a FAT32 partition. Further BIOS development could include multiple CP/M partitions (i.e. "disks"), seamless FAT32 support and/or CP/M 3. In the meantime, testing on the base BIOS and utility programs (i.e. clock routines etc) continues.

The 36.864MHz over-clocked version is being tested for reliability and so far there are no issues. It's about 10% faster than the 33MHz version and will also allow for serial communication at 230,400 baud. Using ASCIIART.BAS as a benchmark, it takes just under 30 seconds at 33MHz and about 27 seconds at 36.864MHz using MBASIC 5.21.

This is probably as small as I'm going to go due to physical component sizes and my desire for two layer boards that I can hand solder with an iron. Further hardware development will probably concentrate on my more general NYOZ system and possibly an eZ80 system.

This board is *NOT* for the soldering novice: all components other than the switch are SMD, there are QFN's (one with 0.5mm pitch) and QFP's with 0.8mm pitch. Although the discrete components are 0603's, several of them are very close together. Since the original boards perform exactly as expected, no rework is planned at this time.

If there is enough interest, I might consider making a small batch of these systems.

http://www3.telus.net/public/wsm/MinZc-1.jpg

http://www3.telus.net/public/wsm/MinZc-2.jpg
Re: A New Small Z180 Board at 33MMHz [message #6569 is a reply to message #6562] Wed, 25 September 2019 07:05 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
Messages: 223
Registered: October 2015
Senior Member
Very sweet - but definitely beyond my soldering skills!

Alan
Re: A New Small Z180 Board at 33MMHz [message #6600 is a reply to message #6569] Tue, 01 October 2019 11:20 Go to previous message
wsm is currently offline  wsm
Messages: 134
Registered: February 2017
Location: AB, Canada
Senior Member
Alan - Thanks for the compliment. I agree it's a neat little system that is definitely worthy of a banked CP/M-3 upgrade. If I get commitments for three of these, I'll build them up and test them for basically my cost: $50US for a 512KB system including source code, an 8GB SD card and shipping. I'd need to know 33 vs 36MHz and 512KB vs 1MB (+$5). I have other projects on the go but they would be in time for a Christmas present.

re: SMD soldering

I used to shy away from SMD as being too difficult and/or requiring new tools until I finally committed to giving it a serious try. I'm simply using a 40+ year-old Weller WTCPN iron with PTS7 fine tips, .015" Multicore solder and liquid flux pens. I also use an old X-ACTO X-TRA Hands magnifier, an X-ACTO knife with #11 blades and a pair of fine tweezers from an old biology kit ... that's it other than .050" solder wick for the occassional oopsie.

For me, the trick to SMD soldering is *CAREFUL* positioning, LOTS of flux and minimal solder. I use the tweezers to position the part and my other hand to hold the part in position using the flat edge/point of the X-ACTO blade. The tweezer hand is then free to add flux followed by the iron with just the smallest amount of solder on the tip.

QFN's can be done by dragging a SMALL ball of solder along the edges / pads. For QFP's, I tack opposite corners then use a "tap" technique on the pads / ends of each of the pins. The SM PLCC socket on this board is a bit of a challenge but the contacts are accessible and hand solderable.

Once a board is complete, one side at a time I flood it with flux remover then let it sit for a few seconds and finally blast it off with canned air. Isopropyl alcohol also works but not as well.
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