TRS-80 Model I

Firstly let me emphasise that my first computer was a TRS-80 Model 1. And I thus do have a soft spot for that machine. Irrational, probably, but there you are. I've got several TRS-80s now (M1, M3, M4, CoCo, M100) and all have proved _very_ reliable. Odd considering other people's expieneces, but I must have replaced perhaps a dozen components _total_ in all said machines. Now, the Apple ][... I had a lot of rpboelsm with it randomly crashing. In the end I took the whole thing apart and stuck an ammeter in the 5V output of the power supply. It turend out that the mainboard (48K RAM) + languge caed + 1 floppy drive drew _more_ than the rated current of the supply as given in the techincal manual If you added more drives, a serial card, etc, it became ridiculous. Much has been said about the Apple ][ disk controlle, and how it's a clever design. Well, a minimal-component design certainly, but I didn't like it. Not having a track0 sensor seemed like a Bad thing for starters (continually banging the head against the stop does not improve the alignemnt!). The drives are Shugart mechanisms with the IMHO poor plastic-cam-with-a-spiral-groove head positioner, and becuase the drives are non-standard you can't use any others (unlike the TRS-80 where you can use any 5.25", 3.5" or 3" drives). But for me the biggest problem was that the Apple couldn't read/write disks from other machines, unlike the TRS-80, which used a WD1771 controller and could handle any single-desity 5.25" disk (I spent many late nights getting it to read the disks from the school's RML380Z computers, which also used 1771 controllers). I didn't like the Apple ][ I/O system. Memory space was tight, but they wasted lots of space with those 'soft switches' and single-bit inputs. It could all have been packed into a few bytes. I am pretty sure the 6821 if not the 6522 was available when the Apple ][ was designed. The first seiral port for the Apple ][ was a bit-banger. It was the only one I had for some time, and it was almost unusable. The TRS-80 used a real UART, and worked. Yes, there were better serial ports avaiable for the Apple later. The Apple text display did have lower case (wich the TRS-80 didn't as standard), but you couldn't mix text and graphics on the same part of the screen. Apple gave you the high-res mode, but working out the addresses gave me headaches (all to save a few chips IMHO!). And colours in the high-res mode were essentially obtained as NTSC artefacts. And another oddiity. The whole design of the Apple ][ seems to have been to save a chip if at all possible (provided the machine still works -- just). And yet the kayboard was encoded in hardware. Why? It meant you couldn't implelement a lower case keyboard in software (there are the well-known shift key mods where you run a wire from the shift keyswitch to one of the single-bit inputs on the games connector, which shouldn't have been necessary). Of course I like elegant, simple designs (the HP9100 is a case in point). But the Apple ][ seems to have been a case of cutting too many corners. And I had a lot of problems as a reuslt. -tony