Decoding BASIC listing

[BeLucid]

Hi everyone. I'm busy learning the VIC memory map and interacting with a few cartridges:

Commodore "8K" RAM expansion that mysteriously behaves like a 16K expansion.
3K Super Expander
Cardram 16K Expansion
Mosaic RAM Master 32K
VIC-MON
HES-MON
Programmer's Aid

All good fun. Learning which use which blocks. Which can and can't be used together. The joy of DIP switches. The ins and outs of the RAM 1,2,3 and the 8K RAM Blocks. Funky Blk #5. All very lovely.

My question arises because I'm trying to use a couple programs in BASIC from the Cardram 16K expansion's manual.

The listing uses some character codes in strings that I'm not used to seeing. I'm used to seeing the graphical representations like in Commodore's manuals and the other code listings I'm familiar with. Instead, the listings in this manual use the following in strings:

{CC} - Character Color I assume (see below)
{CD}
{CL}
{CR}
{HM}
{RV} - Reverse On I assume
{RO} - Reverse Off I assume
{SC}

I assume CC is character color because there are a bunch of REM lines at the end of the program that tell you what the color value of CC is for each place it's used:

10430 REM LINE 10010, 10160, 10130, 10330 CC=BLUE
10440 REM LINE 10210, 10240, 10350 CC=RED
etc.

So rather than literally {CC}, I'd press CTL-# for the color.

My question is what do these other codes mean? What should I be typing. I have a theory that C is for the Commodore key (except for CC), and so {CD} is Commodore-D and {CL} is Commodore-L. Which would mean {SC} might be Shift-C. Is that right? What the heck is {HM} then though?

Maybe this was a somewhat standard way of doing listings, and I've just never seen it and learned the decoder ring. Any help on what I should type for these is greatly appreciated!

Cheers,
Sean

[GreyGhost]

CD = cursor down
CL = cursor left
CR = cursor right
HM = home
SC = screen clear

This would be my interpretation anyways.

[BeLucid]

Thanks Rob. Those make good sense. I'll give them a shot!

[BeLucid]

One more character that I don't know what it is or how to type it in. It looks like a cross between a 5, a 7 and a kanji character.

It's on pg. 26 of the PDF (A10 of the original manual) here: http://www.bombjack.org/commodore/hardw ... VIC-20.pdf

It's in the 2nd line in the Z$ string.

Anyone know what that is and how to type it?

[buzbard]

If you look at page 2 of that manual you will find the answer to your first question.
And, if you read the last line of the listing on page (A10) it will give the answer to your last question.

Code: Select all

10480 REM LINE 10010 THE 'MUSHROOM' IS A SHIFT C

[BeLucid]

So you are saying I should RTFM Ray?

In my defense.... I found the online manual to link to it, but didn't read it online, I have a paper manual, and it doesn't have that same page 2. My page 2 has the "WARNING" part, but not the key.

There was either another edition of the manual that had the decoder key, or whoever digitized the manual added it in.

I'd read the mushroom REM early on but for some reason didn't make the connection. Now that I look at it a 2nd time, (and notice that's the line # the mushroom referred to), I see it.

Thanks!

[buzbard]

So you are saying I should RTFM Ray?

Well, I didn't intend for it to come out that harsh, but, I guess that's essentially what I meant.

[BeLucid]

Thanks Rob and Ray. I did get it typed in. (First try, woot!)

It's a nice little display. It was fun to try it out with all the different RAM options. I can't say it added much to my understanding beyond what I got reading that manual, but it was neat none the less.

Two days ago I'd never thought about the VIC-20 memory map, and now I think I have it all figured out and stored in my wetware RAM. Mission accomplished!

Moving on...