Ken, yes, I have a better routine in place now! Learned the very hard way…

The extended Star Saga game sounds cool! I do want to make it to KansasFest some year.

Peter, thanks for that link – I’ll definitely check the lecture out – I’m kind of surprised Macrosoft didn’t catch on back in the day – at least, I haven’t run across many mentions of it being used, despite the fact it seems a very solid tool.

I’m curious as to where that spaceship design came from. It’s too cool not to know!

http://www.bluerwhite.org/tag/macrosoft/

As for Star Saga, if playing solo is an issue, then you should go to KansasFest! They started a Star Saga game there that they expect to pick up and continue at each consecutive KansasFest for years to come. I’m sure they’d welcome another player!

“Rest assured that the computers offered in trade are purely nonsentient devices suitable for repetitive tasks such as industrial process control, high-speed calculation, and the creation of works of interactive fiction.”

It’s pretty easy for HGR…
Essentially you need to figure out your ROW address then add to it your column address. Sure there are lots of silly algorithms to calculate the Woz’s complicated framebuffer layout but most people just use a lookup table. i.e. have two lists of bytes in memory, one representing the low byte of the initial address of each hi-res row and the other representing the hi-byte. Then do something like this:

LDX #COLUMN ; It’s best to think of the hi-res screen as 40 columns of bytes where every bit in the byte (except for the “7th”) is a monochrome pixel. On a colour screen each pair of pixels can be arranged into one of four patterns which make a colour – The 7th bit of the byte the pattern resides in could be thought of as setting the “pallet”

LDY #ROW; This is more straight forward as each byte of screen memory writes to a single horizontal line on the screen.

LDA $LOWTABEL,Y; $LOWTABLE here is an address in memory which has the low byte of each row.
STA ZEROPAGE; Store it to some zeropage location.
LDA $HITABLE,Y; This is a table of the high bytes
STA ZEROPAGE+1; Store it to the next zero page location

LDA #BYTEYOUWANTTOWRITETOTHESCREEN; Take the value you want to store into screen memory and load it into the accumulator

STA ($ZEROPAGE),X; This writes it to the desired row or column of the screen.

Mike.