Monday, 1 July 2013

Kevin Savetz's book

As a slightly relevant aside, I did get a prize in the last RC, kindly donated by Kevin Savetz (I'm guessing this is him :) ). Signed copy, no less.

If you ever want an entertaining read and you are a 70s/80s computer geek, it's highly recommended.

Actually a lot of the book could be about me, (if you cross out where it says "Atari" and replace it with "Sharp MZ-80K and BBC Micro."), I never owned any Atari kit before an Atari ST.

First release of Assembler and Emulator

The post title gives it away really.

I've added to the links bar links to zips of the Assembler and Emulator for the Funtronics hardware.

These should be very much considered v0.1 (actually they are .....) but they do work, admittedly you can't do much with them, yet.

The souce is set up for Eclipse and both were developed under Java 7, though 6 will probably work. (not so sure about the audio)

The emulator has no actual hardware so whilst it will run COP411 binaries it won't interact with anything external.

Finding a graphic for Assembly Language isn't that easy and I came up with this stack. I can't really see a HLL for this machine being developed - but having said that, there's a machine called the "Gakken GMC-4" you can get which is a 4 bit Microcomputer based on a Tandy (Radio Shack) trainer from the 1980s. Someone wrote a GCC back end for it and someone else wrote a Basic compiler. So you never know. Given that it has about 80 bytes of program memory (4 bit memory at that) you couldn't do much with it (but then you couldn't with Atari 2600 BASIC either ....)

So, anyway, the next thing is to develop the hardware interface.  This will probably be integrated into the assembler, because there is no consistent hardware for this machine, merely a bunch of LEDs, switches and buttons that appear in various places on the game box.  So there will be some sort of descriptive language for that that is integrated into the assembler.

The hardware will be a sort of crossover between Jacks and Red Light Green Light. It will take the basic design of RLGL and add to it the option of the keyboard matrix in Jacks.  While the patents are pretty similar, there are silly design differences - in RLGL the power switch is connected to G2 and the speaker to G3. In Jacks the power switch is connected to G3 and the speaker to G1. (Port G is a configurable I/O port).

I did have the idea of making the design completely configurable but I thought that was going a bit far. I will basically stick with the RLGL hardware  (4,296,926) with the Switches 16a-f added as in Jacks (4,355,806).  This will be extended slightly on both, so that there are a possible total of 8 switches mapped to L4/L5 and D0/D1/D2/D3 (giving a total of 8 switches, and G0 and G1) and 16 LEDs - with their anodes driven by L0/L1/L2/L3 sinking into D0/D1/D2/D3.

Working COP411 Emulator

As the post title implies, the emulator for the COP411 is now working and here it is.

One oddity is that whilst there are only 32 nibbles of RAM, the mapping actually allows for 64 bits of RAM (Bd is 4 bits, Br is 2 bits).

A consequence of this is that in the map every nibble appears twice - e.g. $00,$08 ... $01,$09 and so on. (The hardware ignores bit 3 of the Bd register).

Now I need to cannibalise the Assembler I wrote for the watch project so it will assemble COP411 assembler. There is actually a working COP411 assembler available, but I want to be able to extend it easily.