[sebhc] Graphics Card

ziloo ... ziloo_1 at yahoo.com
Tue May 15 10:30:26 CDT 2007

When collecting bite and pieces of information about H-89 on the net, I came across
this note from some folks:
"The base H-89 had no graphic modes, just 33 graphic characters. At least two different
add-on boards were created that gave the H-89 bitmapped graphics capabilities, but 
I'm pretty sure they both required hardware modifications to tie them in to the 
terminal board - this was not a simple plug-in expansion card." ...
  "There's a 3rd party graphics board fitted on top of the CRT (seriously). 
It links into the PSU/video cableform from the Terminal logic board to
the monitor, and also into 8 of the RAM chip sockets on the CPU board.
The RAMs you pull to plug in the cables go into the graphics board, 
which contains another 16K of RAM as a bitmapped display buffer." ...
  "OK, the manual says 'Micronex Pixelplotter Graphics on the Z89/RFI 
computer'. It also says 'Micronex Limited, Harford Square, Chew Magna, 
Bristol, England'. I've got the installation instructions and memory maps.
The thing contains 16K of RAM which is bank-switched with 16K of the 
normal memory. I think my board uses port F2H, bit 3 to select the new 
16K, but I'm not absolutely sure." ...
  Has any of our SEBHC folks been familiar with any graphics add-on
feature for H-89 system?

Pinpoint customers who are looking for what you sell. 
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