Differences

This shows you the differences between two versions of the page.

--- boards:sbc:sbc_v2:sbc_v2-004 [2019/08/17 16:32] – Initial import from Wayback Machine
+++ boards:sbc:sbc_v2:sbc_v2-004 [2026/06/15 12:54] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 /* Imported from Wayback Machine
    Original URL : https://retrobrewcomputers.org/doku.php?id=boards:sbc:sbc_v2:sbc_v2-004
-   Snapshot date: 2019-08-17
+   Snapshot date: 2025-10-15
    Generator    : wayback-archiver
 */
-====== SBC-V2-004 ======
+====== SBC V2-004 ======
-//Under development://
+The SBC V2 is a Zilog Z80 processor board. It's a 100x160mm board that is capable of functioning both as a standalone SBC or as attached to the ECB bus.
-Updated design to include the following changes.
+Previously known as the N8VEM SBC, development began in 2006 wth V1 and is currently still in development.
-Correction of reset circuit.
+====== Features ======
+Mhz+ Zilog Z80 CPU.
+Up to 512Kb paged SRAM.
+Up to 1Mb EPROM or 512Kb Flash ROM.
+Serial Interface.
+IDE interface.
+Real Time Clock.
+Onboard sound.
+Battery backup for RTC and SRAM via super capacitor.
+Standard ECB bus interface.
++5V power connector for Single Board Computer operation.
+Reset button.
+Status LED.
+Switchable clock speed.
+====== Pictures ======
+{{[[lib:plugins:ckgedit:fckeditor:userfiles:image:boards:sbc:sbc_v2:sbc_v2-004:gallery:sbc-v2-004z.png]]
+====== Changes from SBC V2-003A ======
 Addition of speaker circuit.
@@ Line 39: / Line 71: @@
 Default to hard Kontron reset mode.
-Other ideas to be considered:
+Add User input button on UART Ring Indicator line (for recovery mode in ROMWBW)
-RAM access over ECB-BUS.
+Elimination of flow control jumpers.
-Renumber all parts.
+===== Software Support =====
-Version V:
+[[software:firmwareos:romwbw:start|ROMWBW]] BIOS featuring:
-{{[[lib:plugins:ckgedit:fckeditor:userfiles:image:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004v-front.png]]
+CP/M / ZSDOS
-{{[[lib:plugins:ckgedit:fckeditor:userfiles:image:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004v-back.png]]
+RAM & ROM disk support.
-Version: R:
+ROM based BASIC, FORTH and Monitor.
-{{[[lib:plugins:ckgedit:fckeditor:userfiles:image:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004r.png]]
+Prebuild disk images
-{{[[lib:plugins:ckgedit:fckeditor:userfiles:image:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004q.png]]
+ROMWBW Eurocard expansion board driver support:
+RAMFLOPPY
+VDU
+CVDU
+VGA3
+Zilog Peripherals
+USB FIFO
+Disk I/O
+PIO
+SCG
+DSKY
+DUAL SD CARD
+MF-PIC
+Most recent Kicad files can be found here: https://github.com/b1ackmai1er/SBC-V2-004
 ====== Parts List ======
@@ Line 120: / Line 178: @@
 |JP3-4 |RAMVCC, RAM CS    |ALL OPEN - ALL CLOSED|ALL OPEN|DS1210 Installed.                                      |
 |JP5-8 |RXD, TXD, CTS, RTS|ALL OPEN - ALL CLOSED|ALL OPEN|MAX 232 installed.                                     |
+|JP9   |RECOVERY          |OPEN / CLOSED        |OPEN    |Pin header to recovery mode button (version Z)         |
 |K1    |A17               |1-2 / 2-3            |1-2     |27C080 EPROM Installed.                                |
 |K6    |A18               |1-2 / 2-3            |1-2     |27C080 EPROM Installed.                                |
@@ Line 128: / Line 187: @@
 |K11   |16K/32K           |1-2 / 2-3            |1-2     |Select top fixed RAM size to be 32Kb.                  |
 |K12   |INTSEL            |1-2 / 2-3            |1-2     |Connect 16550 UART to interrupt line.                  |
-|K13   |RSTSEL            |1-2 / 2-3            |2-3     |Select KONTRON reset method.                           |
+|K13   |RSTSEL            |1-2 / 2-3            |2-3     |Select KONTRON reset method. (Removed)                 |
 Jumper Descriptions
@@ Line 197: / Line 256: @@
 The Retrobrew ECB bus is based on a design called the Kontron bus,. Early Retrobrew ECB bus and board designs incorrectly implemented the RESET circuit design. This jumper allows the SBC V2 to be configured for the corrected design call KONTRON or the older design (LEGACY / N8VEM). All board in a system must use the same reset style. Most newer boards have an option to select either style but older boards are hardwired for LEGACY / N8VEM style reset.
-Jumper 1-2 for LEGACY / N8VEM style reset or 2-3 for KONTRON style.
+Jumper 1-2 for LEGACY / N8VEM style reset or 2-3 for KONTRON style. Option removed in final version. Now hardwired for KONTRON mode.
+\\
 ====== Connectors ======
@@ Line 203: / Line 264: @@
 ====== Resources ======
-Version U is experimental. Boards have been ordered for testing 21/6/2019
+Version Z includes fix for clock divider pullup and widens power traces.
+[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004z-schematic.pdf|:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004z-schematic.pdf]]
+Version U.
 [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004v-schematic.pdf|:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004v-schematic.pdf]]
@@ Line 213: / Line 278: @@
 [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004v-kicad5.zip|:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004v-kicad5.zip]]
-Version Q designs have been manufactured and proven good. Version R corrects the silk screen erratta.
+Version Q designs have been manufactured and proven good. Version R corrects the silk screen errata.
 [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004r-gerbers.zip|:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004r-gerbers.zip]]
 [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004r-kicad.zip|:boards:sbc:sbc_v2:sbc_v2-004:sbc-v2-004r-kicad.zip]]
-[[https://retrobrewcomputers.org/lib/exe/fetch.php?tok=483ee5&media=https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/sbc_v2/sbc_v2-004/sbc_v2-004-snd.png|{{https://www.retrobrewcomputers.org/lib/plugins/ckgedit/fckeditor/userfiles/image/boards/sbc/sbc_v2/sbc_v2-004/sbc_v2-004-snd.png?386x300}}]]
-{{[[lib:plugins:ckgedit:fckeditor:userfiles:image:boards:sbc:sbc_v2:sbc_v2-004:zxturbo-v2.gif]]
 ====== Errata ======
-Silkscreen mixed up for R1 and R2 resulting in reset button failing. R2 should be resistor closest to reset jumper and should be 10K. R1 is resistor closest to reset switch and should be 10R. Lots of silkscreen reverted to Fab layer somehow. Fixed in revision R
+Version U - Silkscreen mixed up for R1 and R2 resulting in reset button failing. R2 should be resistor closest to reset jumper and should be 10K. R1 is resistor closest to reset switch and should be 10R. Lots of silkscreen reverted to Fab layer somehow. Fixed in revision R
-\\
+Version V - CPU oscillator may not work due to incorrectly placed pull up resistor. A 1k resistor needs to be added between pin 12 and pin 14 of U26 74LS06.