Improved Corsham 6809 Processor Board REV 5
For comparison this is an actual Corsham 6809 Processor Board.
Bare board of reproduction Corsham 6809 Processor.
This is an enhanced reproduction of the Corsham 6809 processor board. Its design was based on the Corsham 6800 REV 4 board. This boards contains 128K of RAM. EPROM consists of a 2764, 27128 or 27256 for the monitor. 8K of the EPROM is mapped to the processor allowing up to four separate monitor programs to be selected by jumpers. Baud rates up to 38400 are now generated. This board can be an excellent processor board to use in either a Corsham style system or to replace an SWTPC MP-09 processor board,
Eprom upgraded from a 2764. Now a 2764, 27128 or 27256 can be used. This allows up to four different monitor programs to be selected by jumpers. You can switch between SBUG and OS9 by changing a jumper.
EPROM decoding was changed to allow for EPROM at E800-EFFF. This allows the Corsham board to match the SWTPC MP-09 which has three 2K EPROMS at E800, F000 and F800.
RAM selection was changed and address decoding was changed. A GAL now decodes addressing instead of an obsolete TTL chip.
Removed the MC14411 baud rate generator and replaced it with easy to find parts. Baud rates of 150, 300, 600, 1200, 2400, 4800, 9600, 19200, 38300 are generated by the new circuit. The only common baud rate that is missing is 110. 110 is typically only used when using a Teletype (Typically a Teletype 33) for a terminal. If you should need 110 baud use a SWTPC MP-09 processor board.
Added an SWTPC style RESET NMI connection terminal. This allows for plug and play in an SWTPC cabinet.
The onboard RAM can be disabled in 64K blocks. There was really very little need to disable memory in 8K blocks.
There were numerous small changes to improve operation with a full size SS50 motherboard.
Uses a ground pour to fill in almost all empty areas of the board with ground.
Key Features
Difference between FLEX for the Corsham System and SWTPC System
Currently the 6809 Corsham SD Shield system and its FLEX adaptation places system terminal IO on slot 1 at address E010. The standard address for most of the SS50 community is E004, which on most systems is SLOT 0. This can sometimes be a problem because some programs write directly to the serial port, bypassing SBUG and or FLEX. This can cause some programs to hang until they are patched. In the next couple of months we hope to have a version of FLEX and SBUG for the SD Shield system that uses the customary address of E004 for terminal IO. Adapting this change should make for more interchangeability between Corsham systems and other SS50 systems.
FLEX
Flex is available for either the Corsham SD Shield or the standard SWTPC configuration with floppy controller and/or IDE controller. The SD shield version does not have any support for a floppy/GoTek drive. It is necessary to use Floppy Maintenance on a PC to add files to the disk images on the USB memory stick. You may also download other disk images from the internet and transfer them to the USB memory stick.
FLEX 9 vs FLEX 3.0
TSC's last release of FLEX was Version 3.0. FLEX 3 was offered for 6800 and 6809 systems. FLEX 3 has minor changes compared to FLEX9, and most will not notice any difference between the two versions. One of the changes was to locate a defined place in memory to replace the enter system date prompt and substitute date entry from a time of day clock. For the SWTPC version of FLEX, the date is read from the PT-SS30-146818 clock board and it is no longer necessary to enter the date. For those wanting the latest and best, FLEX 3.0 is it, but in reality there is little difference between FLEX3 and the later version of FLEX 9.1 or the later versions of SWTPC FLEX. A version of FLEX3 for the SD card system will be offered later. That version will read the date from the clock on the SD card system and will no longer prompt for the date.
NitrOS9
NitrOs9 has been debugged and it working on a test system. The two biggest problems were the serial port was being initialized before the DAT. This resulted in the serial port not being initialized and this had the possibility of the system hanging during boot. The other major problem was the SD Card system was not ready soon enough and hand shaking between the processor and the SD card system was not functioning when the processor attempted to load NitrOS9. This also resulting in the system hanging during boot. The solution was simple enough, a pull-down resistor makes the processor wait until the SD card system is ready. The release posted has the developmental release message removed and the IO slot has been moved to SLOT 0. Until FLEX is released with IO in slot 0, you can simply put jumpers to select the serial port at 0 and 1. Then FLEX and NitrOS9 will work without changed jumpers for the IO card.
OS9
At the moment OS9 is not supported on the Corsham SD card. OS9 needs these SS30 boards to function: FD2 floppy controller, PT-SS30-IDE, serial board, PT-146818 clock board. The only way to run this many IO cards in a Corsham system is to use the Corsham SS30 extender. Initial testing with the SD Shield and NitrOS9 was not satisfactory, with the system locking up from time to time. A quick move of the Corsham SD NitrOS9 shield driver to OS9 did not allow OS9 to work any better using the Corsham SD shield. We hope at some point to debug and offer OS9 and/or NitrOS9 for the Corsham SD shield. For now OS9 will require a system with an SWTPC motherboard or a Corsham motherboard with SS30-Extender. The Corsham REV 5 processor board runs OS9 fine in either an SWTPC box or a Corsham motherboard with the previous listed IO boards. Corsham boards R4 and earlier can't handle the addresses used by the OS9 Boot ROM E800-EFFF and F800-FFFF.
Downloads
Hardware and Installation Manuals:
SS30-IDE quick start Quick Start Guide FLEX/OS9 from SD on SS30-IDE
Flex Installation Installation Guide - FLEX to SD on SS30-IDE
OS9 Installation Installation Guide - OS9 to SD on SS30-IDE
NitrOS9 Installation.pdf NitrOS9 Installation Guide
EPROMS
For Corsham Systems:
xSBUG-Corsham SBUG for Corsham SD Shield (SRC + BIN)
Corsham-NitrOS9-Boot.bin NitrOS9-Boot NitrOS9 boot rom 2764
For SWTPC Systems:
SBUG182-SWTPC.BIN SBUG1.82 supports floppy and IDE Boot (BIN) - for REV5 and later
SBUG.ASM S-BUG 1.82 Source with IDE Boot Command
WDISK.TXT - Source Code -HD Driver
GoTek Utilities:
FloppyMaintenanceSetup.zip This Windows program can convert .dsk to .ima formats. Import and export files. Move files from one .ima image to another by use of import and export.
Click Here GoTek IMG.CFG File The configuration file you need for your GoTek to support FLEX/OS9 formats. UnZip and place on your USB memory stick.
GoTek and SD Images
For Corsham Systems:
Corsham SD Memory card image Download, unzip and place the contents on a micro SD card. You then need to move the contents of the 6800 or 6809 folder to the root before the SD card is usable.
NitrOS9 SD memory card.zip NitrOS9 SD Memory card image Download, unzip and place the contents on a micro SD card.
For SWTPC Systems:
FLEX 3.01 Updated 5/25/24 FLEX Boot Disk - IDE support - 80 TRK
FLEX 3.01 Source Updated 5/25/24 Flex 3.0 Source Code for SWTPC - 80 TRK
FLEX Installation Instructions to transfer FLEX 3.0 Boot disk to SD
FLEX291.IMA GoTek image, SWTPC FLEX 2.91 BOOT DISK - NO IDE support
Software Manuals - FLEX:
FLEX 6809 User's Manual.pdf FLEX 9 User's Manual
FLEX 6809 Advanced Programming Manual.PDF You need this if you want to write programs.
ASMB6809.PDF FLEX 6809 Assembler Manual
XBASIC.PDF TSC XBASIC User Manual
BASIC.PDF TSC BASIC User Manual
INTROL-C.pdf Introl C User Manual
NitrOS9
NitrOS9 Installation.pdf NitrOS9 Installation Guide - Updated 9/5/24
Getting Started With NitrOS-9.pdf
NitrOS-9 Operating System User’s Guide v03.02.01.pdf
NitrOS-9 Technical Reference.pdf
NitrOS9 SD memory card.zip NitrOS9 SD Memory card image Download, unzip and place the contents on a micro SD card.
Corsham-NitrOS9-Boot.bin NitrOS9-Boot NitrOS9 boot rom 2764
OS9
OS9 Manuals:
OS9 Users Manual.PDF OS9 User's Manual 1983
OS9 System Programmers Manual.PDF OS9 System Programmers Manual 1983
OS9 Assembler Manual.PDF OS9 Editor, Assembler and Debugger Manual
OS9 Basic09 Manual.PDF OS9 Basic User's Manual
OS9 C Compiler Manual.PDF Microware C Compiler User Manual
OS9 Scred Users Guide.PDF Full screen editor for OS9
EPROMS - OS9
Boot for use in SWTPC System or Corsham with SS30 Extender
Copy to a 2764 or to part of a 27128 or 27256.
OS9BootROM File size 8K, program located (0800-0FFF,1800-1FFF)
GoTek Images - OS9
Boot image for OS9 OS9 Boot Image - 80 trk
OS9 Installation Installation Guide - OS9 to SD on SS30-IDE
| C-6809-Bare | Corsham 6802 Bare Board+PAL | $25 |
| C-6809-ASM | Corsham 6802 Board assembled with RAM and EPROM (2764) | $99 |