miriam_e | knights

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I got stuck trying to draw a cartoon of a knight for a short job so looked on the net for pictures to help. In my searches I stumbled across this extraordinary site. Knight's Armoury It is a pity I don't have more time because I could spend ages here. I am not the slightest bit interested in medieval times or war or weapons, but the detailed information here on how to make "ancient" knights' armour is fascinating. If you ever wondered how those suits were made, then take a look, but don't blame me if you spend hours. :)

Jenna. You're in the SCA (Society for Creative Anachronism). You'd love this stuff.

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From:

miriam-e.livejournal.com

Heheheheh It really works.
I tried it with the CoCo2 emulator downloadable from
http://discover-net.net/~dmkeil

It requires a tiny bit of setting up. You have to make sure the Disk BASIC cartridge is loaded (don't forget to Shift-F10 to cold reset) then load the game into the virtual disk drive, loadm it, exec, and you are away!

Paul Hoffman was a CoConut too? Cool! :)

I didn't sell any CoCo software. My machine was mostly used to fiddle with fractals and chaos.

On my lap right now is a big folder I wrote of hundreds of handwritten pages of the CoCo ROMs I disassembled and commented. Ahhh the good old days, when obsessive-compulsive was being focussed instead of a disorder. :) (Not that I'm truly OCS... at least I don't think so... well, sure, I used to step only on, or only between, the cracks in the pavement, but everyone does that, right? :) heheheh

That CoCo gave me a lot of fun. There were a number of hardware projects I built for it. I noticed that a couple of gates could be hooked up to the video to make a black screen with green writing. I built a ROM burner that plugged into the cartridge port. I made a microphone that used the CoCo's cheapo D to A converter with its analog comparator to digitise sound. Later I got disk drives and OS9. Man! That was a wonderful operating system! Multiuser, multitasking, OS in less than 64k!!!!! Very cool. Let the kings of software bloat digest that!

Most of all I loved the 6809 processor. Writing assembly code for it was almost like writing a high level language.

[Sigh!]

Memories.

From:

revbobbob.livejournal.com

Wonderful news. Hope you like it.

About the 6809, it was a dream. I still get a sensuous thrill out of thinking about "LDA". The condition codes were written by the angels: if you have to do a compare on the 6809, you're just not trying. And the addressing modes! The instruction pair for NEXT in the FIG-Forth compiler (which I used for my Forth-83) was:

LDX ,Y++
JMP [,X]

I also have an anally commented ROM listing. There was some seriously cool stuff in those routines. I remember Bill Gates (or whoever actually wrote it) having

LDA #$4C
BEQ somewhere

which at first glance looked stupid (the immediate would set the condition code to nonzero) but the cool think about it was that 4C was the code for CLRA, which would set the Z bit in the condition code, so you could jump to the middle of that instruction and go somewhere different. They had a CMPX followed by no branch instruction that did something similar, I recall.

However, I must bow deeply in your direction for your hardware escapades. My hardware hackery consisted of putting in some piggyback RAM and putting a piece of tape over one of the pins of a ROM pack so you could disassemble it. But you did the real thing.

I am not worthy!

From:

miriam-e.livejournal.com

I still get a sensuous thrill out of thinking about "LDA".

heheheh You sick fellow. :)
6809 is definitely an amazing processor. The degree of orthogonality in the instruction set is amazing. It's possible to write incredibly tiny bits of code that do a tremendous amount. And I love the way it's no effort at all to write 6809 code that is completely position-independant. That was a real revolution at the time.
I just went back changing "was" to "is" in all that, because of course the 6809 still exists and even better versions exist now, like higher speed ones, and static ones (if I remember rightly), and even versions with onboard ROM, RAM, port chips, and timers.

Yes, I remember looking at that NEXT code in the 6809 FIG FORTH and being amazed. At times the 6809 almost looks designed for FORTH with its two stack registers.

FORTH is a brilliant language. If it wasn't for its reverse polish notation it would have conquered the world long ago. Its list of capabilities are mind boggling:
- tiny, fast executable (4k for the standard language on most machines),
- can be easily and infinitely extended,
- interpreted (interactive) and compiled (small, fast) with no explicit compile stage
- close to the metal (there are a series of processors that actually have FORTH as their machine instruction set!!!)

I've often wondered if it is possible to make a FORTH-like language that doesn't use RPN. That would be really easy to use. But I've never really sat down to explore the possibility. One day I will.

Yeah, I remember those weird instructions in the CoCo BASIC ROMs. I think they had similar code sequences in the Z80 TRS-80 ROMs too (of which I also have voluminous disassemblies also :)

One thing I've always been very attracted to was self-modifying code. But it is very easy to get into very deep water very quickly with that.

:) My hardware fun was not great. The EPROM burner was basically just an Intel port chip that I liked (can't remember which one without digging it out -- yes, I still have it) and a transistor to switch the higher voltage for the burn signal. Everything ran under the CoCo's control, even all the timing, using a simple assembly program. The new VDG mode was just an extra 74LS157 quad switch that altered the signals on some of the video chip's pins. I controlled it from an unused line on one of the PIAs.
Very simple stuff. Other people have done far better hackery.