LB-MEM-02
Contents
Features
- 32KB SRAM
- 16KB EPROM
- Headers to select PROM bank
- Connects to Address/Data and Memory control lines
- 50x75mm card
Design
SRAM
EPROM
- ATF16V8B part
- TL866ii_Plus_Programmer
- LB-65CXX-01 card has 16 KB PROM from 0xC000-0xFFFF
- LB-6802-01 card has 16 KB PROM from 0xC000-0xFFFF
- LB-6809-01 card has 16 KB PROM from 0xC000-0xFFFF
- LB-Z80-01 card has 8KB PROM from 0x0000-0x1FFF (upper 8KB is not used)
Parts/Jumpers
- Square pin is pin 1
27C256/27C512 EPROMs
- Card has a 16KB size from the CPU
- 27C256 (32KB) and 27C512 (64KB) Flash EPROMs are commonly available
- Jumpers allow firmware banks to be selected
- 2 banks in 27C256
- 4 banks in 27C512
EPROM | SIZE | BANKS | J6(A15/Pin1) | J2(A14/Pin27) | BANK # | LOAD OFFSET |
---|---|---|---|---|---|---|
27C128 | 16KB | 1 | 2-3 (GND) | 2-3 (GND) | 1 | 0x0000 |
27C256 | 32KB | 2 | 2-3 (GND) | 1-2 (VCC) | 1 | 0x0000 |
27C256 | 32KB | 2 | 2-3 (GND) | 2-3 (GND) | 2 | 0x4000 |
27C512 | 64KB | 4 | 2-3 (GND) | 2-3 (GND) | 1 | 0x0000 |
27C512 | 64KB | 4 | 2-3 (GND) | 1-2 (VCC) | 2 | 0x4000 |
27C512 | 64KB | 4 | 1-2 (VCC) | 2-3 (GND) | 3 | 0x8000 |
27C512 | 64KB | 4 | 1-2 (VCC) | 1-2 (VCC) | 4 | 0xC000 |
Backplane Connector
Mechanicals
Rev 3
Rev 2
Rev 1
Checkout
Rev 3
- Adds PWR and GND on U1 (74HC04)
- Adds electrolytic cap footprint
Rev 2
- Flips 74HC04 orientation
- Missing PWR and GND on U1 (74HC04)
- Tested with LB-6809-01 card
- Works
Rev 1
- Missing PWR and GND on U1 (74HC04)
- Added PWR and GND wires to nearest pins with PWR and GND
- SRAM passes in TL866 in SRAM test mode
- Test using ramLoop.asm software
- ramLoop.asm code works on 6809 Emulator
- Forcing an error works
- Check on card without SRAM
- Controls/data look OK
- ramLoop.asm code works on 6809 Emulator