Slice of Pi?

[Mark]

IIRC I had an alternative with better perforamance at a lower price. However it wouldn't run the copy of Elite that I had since it wrote directly to the controller.

[brass monkey]

That's a memory jogger, I had an RML 380Z at work. I've also got a block of about 20 of these -

do I keep this crap?

[Nightjar]

After they were first announced, the demand was so high that Acorn stopped accepting orders except from schools, so that they could meet the commitments they had made to the BBC. Only those private customers who had pre-ordered within a day or two after the announcement got one until they started accepting non-school orders again.

Colin Bignell

[Clive George]

I had a 1770-based controller (think it was the Watford Electronics one

- who did they nick it off?). It could read the elite disk and hence run it (and did it save to the same disk?). It couldn't run the Elite disk cloning program I had.

[John Rumm]

Yup I see what you mean...

Mostly stack related IIRC - things like enter / leave, and pusha / popa

Not used one since the mid '90s (It (well 5 of em!) ran the software I wrote for the the main box controlling the comms system on the EH101 Merlin Helicopter)

[Mark]

Probably one of those. I also had a 3" floppy disk drive IIRC. These never caught on so I swapped to a 5 1/4".

Since the beeb had a proper driver API for the disk I/O there was no need for this.

[dennis]

Don't forget that some disks were formatted to different numbers of sectors on some tracks as a copy prevention measure. I doubt if the inbuilt API supported this.

[The Other Mike]

Not sure about the RX-80 but the FX-80 was IMHO better in some respects than the later Epson dot matrix printers like the FX-800 in that it didn't waste a fold of paper as the tractor drive mech was before the print head.

I think I've still got it somewhere and probably a box of paper, this printer was also fitted with an IEEE488 interface for outputting the results from some automated test equipment.

[The Other Mike]

What the 6502 did, it did fast although you might need a bit more code than the Z80. One area that was not immediately obvious until you started probing through the datasheet was the number of clock cycles per instruction, I seem to recall a few taking over 20 clock cycles on the Z80, the 6202 was about four or five max.

[Bob Eager]

Going back to the early IBM PCs and compatibles, did anyone else swap out their 8088 for an NEC V20 (or the 8086 for a V30)? These were pin and software compatible, but had a barrel shifter for faster multiply and divide, as well as the additional 80186 instructions. It also included an

8080 emulation mode.

[John Rumm]

There were certainly a few commercial machines with them, can't recall many people swapping them though.

They were 99.9% software compatible, but they did fix the double override prefix bug[1] in the intel devices. It did not have much practical implication (since the workaround for the bug on the 8086 did not hurt on the NEC chips), but it did mean you could detect what you were running on (and hence take advantage of the extra capabilities if you wanted).

[1] on 8088/6 if you interrupted the execution of an instruction with two override prefixes such as a repeat, and a segment override, execution after the interrupt would fail to return to the interrupted instruction and instead continue from the following instruction. So time consuming operations like string moves or stores, could fail to complete as expected...

[The Natural Philosopher]

pretty sure the second computer I had was a V20 IBM clone - one of the first clones to be available IIRC.

Ran DOS OK and I used it to do this and that...wrote a lot of code on it for sure.

[Bob Eager]

I put a V30 in my Advance 86, and a V20 in my next machine. It was usefully faster with the kind of stuff I was doing.

[Mike Tomlinson]

En el artículo , Bob Eager escribió:

It was quite a popular upgrade for the Amstrad PC1512 and PC1640 - their first PC compatibles.

[Mark]

I disagree. They did this anyway. All the copy protection did is stop people using legally purchased software.