Recent content by spiderx

Very interesting. I'm thinking this might be used to calibrate the suppository testers, not testing suppositories. That would make sense, as the person would most likely have to visit the site, so they need something portable, and test the tester to ensure it is working properly. It probably has...

The roms are connected to the address space, and normally are not relocatable due to using absolute addressing in the machine code.

I thought it was 3khz for the test tape. There's websites that sell them. Around $50 or more.

Yes, the serial port can go at 38400, but I'm interested in using the RS232C port because I have some older devices that I'd like to try connecting it to (like a Tandy Model 100).

Generally, when troubleshooting a boot issue, you want to look at three things, to start: Power, Clock, Reset. Check that the voltages are correct, check the clock is generating a valid clock, and that the reset is acting properly. Is it coming out of reset, is it activating reset? Based on what...

If it was available, I'd order one, thanks for the link.

If the batteries are good, but the ram disk isn't working, you might have some bad components in the ram disk. It's 40 years old, so well past the capacitor lifetime. Check caps, resistors, etc - verify the test points get the proper voltages.

Just an update, I can set the 'transmit character delay' to 1ms, and enable DTR, and on the HX-20 use LOAD "COM0:68N1F" and that will transfer a bit faster, though it seems slower than 4800 imho, it works.

So, I made a serial null modem cable for my HX-20, as I wanted to test if the serial port was working. It seems like it is. Here's how I did that... I basically got a DIN-8 (full size) cable (I think they sell these for midi) and cut it in the middle, then stripped the wires back and used one...

Technically, you could use one 16k rom in the expansion unit, but not three.

No, the guy who wrote it said it was assembly, and he also wrote a telecomm part to it, though I haven't found it yet. I'm not trying to do that, sorry for any confusion. https://www.vintagecomputer.net/fjkraan/comp/hx20/memoryMap.html According to this, if I set it to 24kb ram (total)...

Just tested, if I set the jumpers on the expansion unit to A,A and dip switches OFF,ON,OFF,ON then it does indeed load to the same mapping as the builtin option rom slot. That makes swapping out the software a little easier, though I cringe every time I swap a rom out when I hear the crunch. It...

You can configure the expansion unit 1 on 2 off 3 off 4 on, to get 16k additional (+ the 16k builtin gets you 32k). That disables the internal option rom port, but... you do get the 13B (at least it reads the FORTH rom and shows it as available) and maybe 14B, but otherwise, you can flip the dip...

Would it be possible to modify it so that it fits in 4000-5FFF? I have an expansion unit, and the extra 16k only works if I disable the option rom on the MOSU. So, if it could be loaded from the option rom on the expansion unit, I could have nearly 32k for forth. Skiwriter also doesn't work...