based on Superfo's works
© 2022 KWF
Date: 22/02/2022
Revision: 0.2
- 2 x 32KB ROM (tested OK)
- 128 KB RAM with ZX Spectrum +2A/B & +3 paging modes (tested OK)
- control logic in CPLD (tested OK)
- AY-3-8910 sound chip controlled with ZX128K ports (tested OK)
- Kempston joystick interface (tested OK)
- RGB video outputs (tested OK)
- RESET button (tested OK)
The schematic diagram is available in the /Docs sub-folder.
If you are interested in hardware's tests and how it works, have a look there: YouTube
The version 0.2 will be open with the schematic diagram and Gerber files available to the publiic. The CPLD impletmentation is closed and the pre-compilied file is available for XC9536XL type only.
Note that any other inteface with its own ROM requires additional wiring around /ROMCS lines (towards TC2068 and incomming from any other extenal interface). The wiring enables compability with interfaces like DivMMC/DivSD. Also the order of interfaces connected to TC2068 is cricital. The first device attached to the computer's edge connector must be TMX128 otherwise it will now work correctly.
The IF has been successfully tested with TC2048. In this case, RGB output does not works due to different signal's alocations on the egde connector. Also a simple modification to TC2048 internals is essential. The missing /BE signal at the TC2048 edge connector needs to be wiried with a short wire from SCLD chip direcly. Pad number 4 on the top side of the main board is not used in any ZX Spectrum machine and it is recommenced for /BE wiring.
Prototype board (rev. 0.1)
Board (rev. 0.2) in tests with DivMMC
No Warranty of the Project. The Issuer makes no express or implied warranty of any kind whatsoever with respect to the Project.
GNU General Public License v3.0 T&C applies to this repository content.