Tim Malcolm had previously indicated that E80 was a Xicor X2804AP-45 chip. That would make it a 512 byte (4096 bit arranged as 512 * 8) EEPROM, rather than an NVRAM, with an access time of 450ns.
Link to datasheet http://pdf1.alldatasheet.com/datasheet-pdf/view/103364/XICOR/X2804A.html This chip should be easily readable by almost any PROM/EPROM/EEPROM programmer, but if it's only got settings as you suspect, then hopefully the firmware would be able to identify a blank device and just set up defaults. Jason -----Original Message----- From: Simh [mailto:[email protected]] On Behalf Of Tim Stark Sent: Sunday, 16 April 2017 1:24 AM To: [email protected]; 'Cory Smelosky' Cc: [email protected] Subject: Re: [Simh] DEC VT emulators on MAME 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: [email protected] [mailto:[email protected]] Sent: Saturday, April 15, 2017 9:43 PM To: 'Tim Stark' <[email protected]>; 'Cory Smelosky' <[email protected]> Cc: [email protected] 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 -> https://urldefense.proofpoint.com/v2/url?u=http-3A__avitech.com.au_-3Fp-3D1818&d=DwIGaQ&c=ilBQI1lupc9Y65XwNblLtw&r=CeQuuq99aEH_1RE1yGnGXY4AbMg6_1cjkYeJjaT-sd4&m=YpwywTuCsVKkSvuZSul6C6BTase_SV-J2yCTQkZVeBQ&s=WAvNJXtV69LsjK_LBZBMcmtmo-gwnd1OPsJy0_seTI0&e= 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. _______________________________________________ Simh mailing list [email protected] https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.trailing-2Dedge.com_mailman_listinfo_simh&d=DwIGaQ&c=ilBQI1lupc9Y65XwNblLtw&r=CeQuuq99aEH_1RE1yGnGXY4AbMg6_1cjkYeJjaT-sd4&m=YpwywTuCsVKkSvuZSul6C6BTase_SV-J2yCTQkZVeBQ&s=bvqLN4m2owRHsY-V572p8fso74T-IQHWY8L1K59aCWk&e= _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
