Ok, I improved my test program to read the data reg and also give some visual feedback: LDAA #$10 ; like in JBUG STAA $8008 ; ACIA control STAA $8022 ; enable 1 digit leds LOOP LDAA #$7F STAA $8020 ; clear display READ LDAA $8008 ; ACIA status ASRA BCC READ ; data ready? LDAB $8009 ; ACIA data STAA $8020 ; display status LDX #$0100 ; delay DELAY DEX BNE DELAY CMPB #'G ; EOT? BNE LOOP SWI The idea is to light a digit for a brief period when a byte is read and have the segments show the status register. Also it should exit if it received the "G". Ok, the G may be *in* a data block but I hardly ever found a G anyway. At least it allows me to tune the volume until I receive something. But it looks random and looking at the leds, like half of the bytes read are framing errors. Obviously, I varied what I could think of (delay, "G", ...) used several recorders (2PCs with audacity, a real cassette deck and two audio cables) Yes, I have the manual and read it through. I'm initialising it by writing $10 in the control reg, which I copied from the JBUG listing. I don't find any reference of a "4053" or similar in the docs of the kit. Yes, dug up my Realistic cassette recorder that came with my TRS-80 but it didn't help. The samples I'm trying to load are recorded with the kit itself. They sound typical and I was able to decode them to binary. As a test, I decoded the jbug rom and compared it to the file from bitsavers. It matched! (except for 4 bytes near the end which are zero on bitsavers an are actually different on my rom). That made me conclude that the 'punch' function is working and the samples I'm using are good. I would like to test with a known-good audio file but I can't find any... I must point out that the kit is expanded and I haven't figured out what it is exactly. The wirewrap area on the processor board has two extra ACIAs and a crystal. I understand the original was a 614.4, this seemed to be replaced by 1MHz and the 614.4 used for the other ACIAs. Anyway, I already swapped them (which did make me type less double characters since I guess the keyboard scan delay is chosen for the original clock speed). The kit came with a Philips Mini-DCR and the cables seem to be made to connect that on the J1 I/O connector. I could go the route of restoring that, but it seems more challenging and it wouldn't allow me to transfer data with the outside world. But I'd like to get at least to the point that I can load and run a program without having to type it in... I also read that the kit allows to connect RS-232, that would be ideal but I don't see how that's possible without adding components and wiring. Wim.