2017-11-16 1:25 GMT+01:00 <[email protected]>: > is there a dif between 40 a and 40 b with the firmware/loader/etc? > Ed# >
I assume there are a difference. The document linked to below at least tell that the original A had a completely different set of ROM chips whilst rev date "April 76" only had the first ROM different. The three others were the same. http://bitsavers.trailing-edge.com/pdf/hp/terminal/HP_262x_264x_roms.pdf > > In a message dated 11/15/2017 12:48:24 P.M. US Mountain Standard Tim, > [email protected] writes: > > I have been working on a HP 2640B terminal. It was mostly about fixing the > "screen mold" problem and cleaning up the liquids that had been seeping out > from the screen down into the bottom. > > The small coaxial wire that connects the 4.9152 MHz clock signal form the > power supply (never seen a crystal controlled SMPSU before!) to the > backplane was broken off, but after fixing that the terminal worked fine. > Just needed some adjustment to the brightness. > > With the correct terminfo installed it worked quite well as a serial > terminal to a Linux box. > > Then I tried the short 8008 programs that Christian Corti pointed to > > http://computermuseum.informatik.uni-stuttgart.de/dev_en/hp2644/diag.html > > and > > ftp://computermuseum.informatik.uni-stuttgart.de/hp/hp2644 > > I tried both a couple of times. The terminal enter the LOADER mode but just > hangs completely at the end. I tried different baudrates but no difference. > > The selftest STATUS line tell me 40<802 which should indicate that there > are 4k memory in the terminal. However there should be 5k since there is > one 4k board and one combined control store and 1 k RAM board. Maybe there > is a fault in the 1k SRAM? The terminal doesn't complain though. > > Regardless, the programs listed either starts at adress 30000 or 36000 > which should then be within the available space. > > The question is, should these program work for the HP2640B as well? It has > a 8008 but my guess is that the firmware is different from the 2644. What > is the joint experience regarding this? Has anyone ran these small programs > above on a HP2640B? > > The HP 2640B firmware consists of four EA 4900 ROM chips which annoyingly > are not anything like normal EPROMs. So dumping will need special > considerations. > > Has anyone dumped the HP 2640B firmware already? I didn't find it on > bitsavers. > > /Mattis > >
