dongfeng
Veteran Member
Does anybody have the DIP switch settings for the IBM EGA card? The 5154 EGA display on my AT is broken, and I would like to replace it (temporally) with a 5153 CGA display.
┌─────────┐
│ 1 2 3 4 │
┌─────┼─────────┤ NOTE: On some boards a jumper needs to be changed for
│ MON │ 0 0 1 0 │ CGA mode (controls pin 2 on DB9).
│ CGA │ 0 0 0 1 │
│ EGA │ 0 1 1 0 │
└─────┴─────────┘
...Not everything can be found in Google in a reasonable amount of time, and Google does not replace a discussion. But there is lots of reference material available already, so rather than rehash or repost what is available elsewhere, let's move up the food chain a bit and generate some new content/new discussion.
Discussions on how packet drivers work, how to modify machines in ways that were not intended, programming on old machines, etc. generally don't appear on Google because it is harder to come by. Those discussions are valuable and harder to find elsewhere.
...The EGA card has a daughterboard that piggybacks onto it, which I assume is to add extra memory. Currently there is one row of chips fitted, and two rows are left empty.
From what I can find out, the card is fitted with 64kB as standard, the expansion increases on this. The chips fitted to mine are labelled as TMS4416-15NL, am I right by saying these are 16kB? To me, it seems a bit pointless in going to the extra expense of the daughterboard only to increase the video memory by 16kB. I was wondering if they would take 64kB chips, making the total 256kB (which seems to be the standard for most aftermarket cards).
It gives the same beep codes when no graphics adapter is installed (and I have since found: http://www.bioscentral.com/beepcodes/ibmbeep.htm ).
I'd love to get an AT Technical Reference, however I've only been able to fint the XT one in PDF format. I'm just going to have to wait until one appears on eBay.
I guess there is no hope for the adapter then
If you have an EGAWonder, why bother with the IBM board at all? The ATI is far superior, IMNSHO. If no other reason, the memory max-es out at 256K vs. the IBM's 128K max (using 16x4-bit wide chips on-board & expansion daughterboard).