An unidentified EPROM, catalogued as “TapeDup”. It is an Intel D2732 (4K) that sat in socket E2 of a John L. Oliger 2716×4 EPROM board (JLO 8309) with many jumper changes, shown in the photos. The label reads “C000 – 0B34”. The only text in the chip is “Copyright December 1982 by Computerware”.
What’s in the download
TapeDup.BIN: the 4,096-byte EPROM image.TapeDup.txt: notes on the chip, socket and label.JLO8309_F1.jpg,JLO8309_F2.jpg,JLO8309_R1.jpgandJLO8309_R2.jpg: photos of the board.
Program Analysis
Only the first 2,305 bytes are used; the rest of the chip is blank. Besides the copyright line at 03C4h, the image holds a narrow character set from 0480h, with digits and capital letters drawn four pixels wide in eight-byte cells. No prompts or messages were found in either ASCII or the ZX81 character set, so what the program does is not known; the code has not been disassembled.
Image Gallery
Note: Type-in program listings on this website use ZMAKEBAS notation for graphics characters.