On Sun, 22 Jun 1997 22:14:38 +0000, you wrote: %I have got plenty of Dragons 32 or 64 for sale/trade/swap if you want %them. I need an IBM Junior and an Apple II. We're on different sides of the Atlantic. Actually, I'm on the east side of the Pacific, so it'd be difficult to actually exchange anything. Looking at the list of articles, there's an answer I owe you regarding the old microprocessors. Go and buy an issue of Elektor from the nearest WHSmith and see if you can order some back issues from the early 1990s. Look for two page ads with lots of component listings. One of the companies is the one that used to advertise older microprocessors. I haven't bought an issue of Elektor for many years now, so don't know if the company is still around. Ben

Due to massive amounts of caffeine & sleep deprivation, e.tedeschi said: [snip] First, I have a question: Was there much difference between the Dragon 32 and the Dragon 64, or is that just a designation of how much memory it had? Also, I have 1 1/2 IBM-PC Jr.'s sitting in my basement collecting dust. They used to be complete, non-working machines (one with a "sidecar" I believe it's called) whereas I did get one "almost working" with spares for the second. The almost working comes in as I didn't have a monitor for them, and altho they did have the RF Modulator to use a TV with, I could never get a clear picture thru that port. I could tell that the machine booted and worked, and I could see changes on the screen so the keystrokes were being recognized, and simple DOS commands did seem to have output, but it was nowhere readable. As such, right now I have 1 complete Jr with floppy drive, sidecar, and 128K mem expansion (I believe... hafta look at the chips & calculate the storage) with an extra internal floppy drive, an extra motherboard, an extra keyboard (neither are chicklet, and one has a few stuck keys) I think there was a Lotus 123 cartridge with it (but I heard rumors that it needed a disk as well?) and a basic cartridge. There may be more stuff, but I haven't looked at it since the move... Are you interested in it? HTH, Roger "Merch" Merchberger -- Roger Merchberger | If at first you don't succeed, Programmer, NorthernWay | nuclear warhead disarmament should zmerch(a)northernway.net | *not* be your first career choice.

There is a little more difference than the ammount of memory - I think the '64 had a built-in serial port (using either a 6850 or a 6551 - I forget which) which the '32 didn't have. As I'm sure most of the people on the list know, the Dragon is very similar to the Tandy CoCo - both were based on the same Motorola Application Note. The main difference is the printer port - in the basic design there were 3 I/O lines left over once the ones needed for the keyboard and video had been allocated. Tandy used them to make a bit-banged serial port (TxD, RxD, CD), while Dragon used them as the Strobe, Busy and Ack lines for a Centronics port. The data lines for said port were the same 8 lines that were used for keyboard scanning - since the printer would only listen when the strobe line was asserted, and the keyboard was entirely software controlled, there was no conflict here. I think I mentioned this before, but I bought a PC-jr for \pounds 10.00 (about $15) at a radio rally earlier this year - the basic machine with IR keyboard, printer 'sidecar', floppy drive and 64K RAM upgrade. I was pleasantly suprised when IBM could still supply the TechRef (about \pounds 50.00). I was even more pleasantly suprised when it arrived - it's a very complete manual - schematics for everything apart from the keyboard and floppy drive (but the latter is in the O&A Techref), BIOS source, keyboard protocol, etc. If you are serious about restoring these machines you should try to get it. -- -tony ard12(a)eng.cam.ac.uk The gates in my computer are AND,OR and NOT, not Bill