[Simh] DEC VT emulators on MAME

[Tim Stark]

Malcolm,

Ok, thanks for let us know.  I now found video docs for VT340 (dragon system - vipers and adders).  Each chip hold one bitmap plane individually. VCB02 graphics card uses the same chips. 

I misread schematics.    I believe that E80 is NVRAM chip for just settings - 512 x 8,  not 512K x 8.  Firmware is in ROM cartridge.  

E49 dump should be labelled as 236E6.bin for CG rom. 

Does anyone have a copy of CRT 9007 video controller docs for VT220 terminal?

Thanks,
Tim

-----Original Message-----
From: malcolm at avitech.com.au [mailto:malcolm at avitech.com.au] 
Sent: Saturday, April 15, 2017 9:43 PM
To: 'Tim Stark' <fsword7 at verizon.net>; 'Cory Smelosky' <b4 at gewt.net>
Cc: simh at trailing-edge.com
Subject: RE: [Simh] DEC VT emulators on MAME

I've now pulled apart a spare non-working VT340, for the ROM dumps. This terminal has a faulty power supply and very significant screen burn, so I wasn't planning on repairing it anyway.

On my board, E80 is a XICOR X2804AP-45 which is soldered in place. So I haven't removed it or dumped its contents.

E49 is a 27256 EPROM.  I have dumped the content of that ROM and it is now available here -> http://avitech.com.au/?p=1818 

That page also has pictures of the VT340 internals.

Tim - I will write to you separately to arrange sending the VT340 logic board to you.

Malcolm.