I have in my posession an Amiga 500, Amiga 1500, WYSE terminal and a Mac Classic.
Today I learned several things:
- PCs running XP can’t read 720k floppies
- Serial communications is still just as confusing as it used to be
- Old hardware doesn’t work like you’d expect
- Given the choice between soldering small, fiddly things yourself, or paying £5 for someone to do it for you, choose the £5 option
One of my aims today was to get my A1500 reading floppy disks, since originally all that happened was an intense squeaking/grating noise would come out the drive, and the computer would have a bit of a fit and complain the disk wasn’t working properly. This was solved, after much faff, by swapping a diskdrive from the A500 and putting it in the A1500. Seems the drives are the same, apart from the fronts of them.
The original diskdrive in the A1500 was quite damaged, either years of fluff and dust had stuck to the read heads, or they were mis-aligned. Either way any disk put into the drive was instantly rendered a dead disk, and received a neat scratch near the edge that went right through the magnetic layer.
PCs won’t read 720k disks any more, so that makes it hard to copy disk images into the Amiga to write them to floppies. After all, writing Amiga floppies on a PC would just be too simple now, wouldn’t it.
The idea with the serial terminal was to hook it up to my Linux machine. This – obviously – meant I had to go out and buy a USB-Serial dongle for my Linux machine, modern PCs having between zero and one serial ports now. Despite being a no-brand one from Maplin, the Linux machine worked out what it was and said it was called ttyUSB0. Now all I had to do was run a getty and connect the serial cable up.
And this is where the trouble began. The cable I have is a null modem cable, with a male DB25 connector on one end, and a male DB9 connector on the other. PC serial ports are also male DB9 connectors.
In Maplin I saw a DB9 Female-Female gender changer, but it was a fiver and at home I have several female DB9 connectors of my own. Surely it’s not hard to make a genderchanger by hand. Yeah, right… whatever. Soldering to those connectors is hard, especially when nobody seems to provide pinouts of gender changers. Do the pins go straight through, as if the two connectors are soldered back-to-back, or do all the pins cross over? I tried both ways and the best I could get was a bit of random garbage in Minicom.
The rest of the day had me trying various cables I own, all of which look like null modem leads, and none of which worked. I will go to Maplin again tomorrow and get a collection of gender changers and serial cables. I want to hook my A1500 up to my PC to transfer files in addition to making this terminal work.
For a test I plugged my GPS into the terminal and after setting the comms parameters, was greeted with NMEA text shooting up the screen.
So, the next time you complain it’s hard making a USB device work, or that it’s such a pain having to install a driver disk, just remember what it used to be like. Is it 19200,8,N,1 or is it 115200,8,N,1? XON/XOFF or RTS/CTS or both? Or neither? And what serial port are you plugged into? And it takes so long transferring files at multi-megabit speeds doesn’t it.
