Differences

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--- boards:sbc:sbc_v2:minimum-build [2018/07/09 10:54]
b1ackmai1er [RS232 Interface]
+++ boards:sbc:sbc_v2:minimum-build [2019/06/10 11:10] (current)
b1ackmai1er [Use flash memory instead of UV-erasable EPROM]
@@ Line 33: / Line 33: @@
   * X1 (32768 Hz crystal)
   * C9 (bypass capacitor)
 ===== NVRAM Controller =====
@@ Line 59: / Line 58: @@
 {{https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/sbc_v2/sbcv2-ttlserial.png?nolink&160x110}}
 ===== Component Substitution =====
@@ Line 65: / Line 63: @@
 ==== Use flash memory instead of UV-erasable EPROM ====
-Flash memory is generally cheaper, easier to obtain, and easier to work with. It could be instantly erased, without UV eraser lamp, it doesn't need special voltages for programming (and theoretically can be reprogrammed in system). The only drawback of the flash memory, is lower storage capacity - 512 KiB vs. 1024 KiB for 27C080 EPROM (this limitation is due to number of pins in 32 pin package). Recommended flash parts are SST 39SF040 (Mouser), and AMD 29F040 (Jameco). Possibly other flash ICs, with lower capacity (such as 29F020, which is frequently found on older motherboards) can be used instead.
+Flash memory is generally cheaper, easier to obtain, and easier to work with. It can be instantly erased, without UV eraser lamp, it doesn't need special voltages for programming and can be reprogrammed in system. The only drawback of the flash memory, is lower storage capacity - 512 KiB vs. 1024 KiB for 27C080 EPROM (this limitation is due to number of pins in 32 pin package). Recommended flash parts are SST 39SF040, and AMD 29F040 (Jameco). Possibly other flash ICs, with lower capacity (such as 29F020, which is frequently found on older motherboards) can be used instead.
 ^Device - Jumper^Size^K1^K6^K8|
 ^AT29C020^256Kb|1-2|2-3|None|
+^AM29F040B^512Kb|1-2|2-3|2-3|
+^AT49F040A^512Kb|1-2|2-3|2-3|
+^SST39SF040^512Kb|1-2|2-3|2-3|
+^M27C4001^512Kb|1-2|1-2|None|
 ^AT27C080^1Mb|1-2|1-2|1-2|
 ^M27C801^1Mb|1-2|1-2|1-2|
+In the situation that you do not have an EPROM programmer it is best to obtain a copy of the ROMWBW in a FLASH format so it can be reprogrammed in-system using the FLASH utility. A HOTFLASH technique can be used if you want to swap from an EPROM to a FLASH chip without an EPROM programmer:
+Example starting with an AT27C080 EPROM and swapping to a AT49F040A FLASH chip.
+  - Transfer new ROM image from PC to SBC-V2 secondary storage i.e. SDCard
+  - Copy FLASH.COM from B: to secondary storage i.e SDCard
+  - Change to secondary storage directory.
+  - Remove EPROM
+  - Change jumpers to suit FLASH chip i.e. K1 unchanged, K6 from 1-2 to 2-3, K8 from 1-2 to 2-3.
+  - Insert FLASH chip. Insert pin 1 side first to ensure GND had contact first.
+  - Run FLASH.COM i.e. FLASH /WRITE SBC.ROM
+  - Reboot
 \\
@@ Line 85: / Line 100: @@
 ==== Disk storage without ECB backplane and Disk I/O board. ====
-You can install the 8255 PPI chip, and use the [[https://retrobrewcomputers.org/n8vem-pbwiki-archive/0/35845334/35845372/35846055/index.htm|PPIDE]] mini board to connect an IDE drive or a compact flash card.
+You can install the 8255 PPI chip, and use the [[:boards:other:ppide|PPIDE]] mini board to connect an IDE drive or a compact flash card.
+{{https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/other/ppide/on_sbcv2_2_.jpg?nolink&400x236|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_boards_other_ppide_on_sbcv2_2_.jpg}}