Hello, all, I have a Tektronix 4052 Graphic Computer that I believe is in workable condition, but the old Mostek MK36xxx-series mask-programmed ROM that holds the operating firmware for the machine have failed, which is apparently a common occurrence for these devices. I have found numerous mention of these ROMs having been used in test equipment that "forget" after 10 to 15 years after production. I found the archive of 4052 firmware on Bitsavers, but am wondering if anyone out there has any suggestions as to what to do to replace the failed ROM with something of more current technology that will work. The firmware consists of 64K bytes of code. The Mostek ROMs are 24 pin devices, 5V supply, that use a clocked chip select signal, meaning that any replacement will have to emulate the clocking access scheme. There were Motorola-made programmable devices that could directly replace the Mostek parts, but these seem to be virtually unobtainable today..and even if I could find 8 of them, I don't have anything that could program them. Any other 8K x 8 ROM is in a 28 pin package, which would require some clumsy adapters to work. Along with the ROM itself, the 4052 had a unique ROMpatch implementation that allowed up to 48 ROM locations to be ''patched' in real time, and this involved a PLA device that did the address matching, and a fast bipolar ROM that contained that data to be substituted at the location to be patched. Duplicating the patched code could also prove to be very difficult. I am wondering if anyone out there may have run into the same situation with a 4052 and came up with a solution. Any help would be greatly appreciated. Thanks, Rick