Questions about a 8328-2 board

[smgrieve]

My board will not select any roms, pad commands all return pad not found. I have replaced IC 31 and 28 with them removed I can select one rom and that one rom will run something seems wrong in the rom section circuit. Also does anyone have the documentation to modify a 8328-2 board for 27128 roms?

[ChickenMan]

Hi smgrieve and welcome to the forum

It is PAK not PAD to call up the eproms. From the Technical manual page 4-3 it says

4.2. Series III and PC85 Additions.
The Series III and the PC85 core boards also have
extra room for PAK EPROMs, either 8K 2764 or 16K 27128
EPROMS.

Which I read that they already support 27128 eproms.  In my PC85 I can take out 2764 and replace it with 27128 with no issue.  The earlier Series 3 as indicated above doesnt need any changes to accept 27128 eproms.

Burn out emu_joust_pc85_h.rom (from the software/roms/games folder in the repo) to a 27128 and put in the socket H as below circled in red.  Then from Basic, PAK 4 should fire up Emu Joust if it can handle a 27128 eprom.

   

[smgrieve]

Unfortunately that didn't work every pak cmd returns, option not fitted. removing IC 31 and IC 28 will make it run as pak 0. PAK keeps getting autocorrected to pad

[ChickenMan]

Can you post a pic of your coreboard showing the 2 ICs you have removed to get PAK 0 to work, as IC 31 and IC 28 are normally soldered in.