British Micros at The Register

NoLand · March 26, 2020, 7:38pm

The Register has an amazing series of well researched articles under the tag “Archaeologic”, written by Tony Smith. If you enjoy a well informed read, including interviews with those who took part, this a great resource.

Here’s a search, which should turn up all the relevant bits of what may be the best pieces of journalism on the British Micro:

https://search.theregister.co.uk/?q=Archaeologic&site=

Edit: @EdS added this handy list of direct links to articles:

cjs · March 27, 2020, 4:18am

Wow, great to see the Dragon 32 so far up there in the Megagraph chart. I’ve always felt that the Motorola 6809 never got enough love. (I FM-7.)

That said, The Reg’s article on the Dragon 32 does have a few omissions.

[PA Technology (PAT) of Cambridge] would further differentiate Dragon’s hardware from Tandy’s by adding a parallel printer port in place of the CoCo’s serial connector… How much of this adjustment was done merely to avoid invidious comparisons between the Dragon and the CoCo, or was a genuine attempt to take a stock design and make a better will probably never be known.

Clearly the latter. The CoCo had no UART and had to bit-bang the serial port. (This was probably the thing that annoyed me most about it, and it was certainly where most of my CPU time went!.) The parallel interface would have been faster and considerably less CPU-intensive, as well as a bit more flexible.

If there’s one further change they could have made, it would have been to add an ACIA (UART) chip, or at least a socket for one, connected to a port on the back. By 1981 not only were BBSs popular (at least among the CP/M crowd), but Videotex was firmly established to the point where the reference design that Dragon was using was originally designed to be a Videotex terminal!

As it stood, especially for 1200 bps communications, for the CoCo you generally had to buy an RS-232 cartridge. This was both more expensive (due to the need for a PCB and case) and used up your one expansion slot. If you wanted to use disk drives at the same time, you’d need to buy a slot expander as well, at yet more expense.

EdS · March 27, 2020, 12:58pm

Some great points here. If you (or anyone) can rustle up a thread about the various 6809 offerings, or perhaps about the Green Thumb and the reference design, that would be great. (I’m also open to splitting your post into a new thread as a starter.)

NoLand · March 27, 2020, 1:15pm

BTW, I had no idea that the Sharp MZ-80A (a machine, I personally have sweet spot for) was such a strong seller in the UK, at one point even at a respectable 10th place. (Where I live, it wasn’t even sold in any shops. I think, you could get it directly from Sharp by a business appointment.)

The Atom peeking just once (and this just barely) into the graph, is a bit sad. (Well, this was probably a bit after its time.)

1983_UK_home_computer_sales-detail