[XCSSA] Any Feb Presentations?

[xcssa@xcssa.org]

I'm jealous.  My wife would kill me if I had all that shit, even confined to 
a particular workbench!

Nick

xcssa-admin@xcssa.org wrote:
> 
> On Feb 11, 2007, at 7:43 PM, xcssa-admin@xcssa.org wrote:
> 
>> I think Thomas King was still planning on the Zimbra presentation... was
>> anyone else going to want to present on anything or not (one week and
>> counting).
> 
> Well, it looks like I'll be down there on Monday anyhow, so I'll bring 
> my Sega Genesis development gear.
> 
> Yes, I finally got tired of working around the limitations of the Atari 
> 7800 and ColecoVision.  So I tried to figure out what the next viable 
> platform was.  The Sega Master System was kind of nice, but consoles  
> were quite hard to find, and therefore it would have a limited 
> audience.  The NES had cartridges with two buses, weird (metric) pin 
> spacing on the edge connector, any but the simplest cartridges needed a 
> "mapper" chip, and then there were the general reliability problems.  Oh 
> yeah, and I never really liked writing 6502 code.
> 
> The next thing in line was the Sega Genesis.  It had the good parts of 
> the ColecoVision (video has its own bus to avoid hogging the CPU bus) 
> and the SMS (like Coleco with 16-color graphic tiles and more sprites), 
> and none of the bad parts of the NES (single cartridge bus, lots of 
> VRAM, video chip ports that don't change function during the display 
> cycle).  Plus it had a 68000, which is simply a kick-ass chip to begin 
> with, no bank switching (at least not until you hit 4 megabytes), and 
> there's still a Z80 in there as a co-processor.  The only negative is 
> that cartridges need to be 16-bit, which means you need either two 
> regular EPROMs or one big 40-pin monster EPROM.  After about two months 
> of working with it, I think the Sega Genesis is probably the easiest to 
> program console there has ever been.
> 
> It also helped that I got a floppy disc game copier for the Genesis 
> years ago.
> 
> What I normally do is test code on an emulator, then when I want to run 
> on the real hardware, I write the code image to a floppy disk, stick it 
> in the game copier and load it.  I also have an RS-232 converter board 
> which can plug into any of the controller ports.  All three ports (the 
> early models had a rear port which was functionally identical to the two 
> front ports except for an opposite gender connector) can be set for 4800 
> baud serial communication.  So I hacked up an old version of Macsbug 
> which I can assemble into the code when I need to do some serious 
> debugging.  I also had a couple of cartridge boards made, so I can burn 
> a pair of EPROMs and play on an actual console.
> 
> Actually, I didn't have one with a rear port handy, but I had the next 
> best thing.  I had a later version of the first model which had that 
> part of the board unpopulated, so I cleaned out the holes, got the 
> appropriate parts from junk boards, and installed them.  I also 
> installed a male DB-9 port instead of the standard female, so I could 
> use the RS-232 board with no changes and no need for a gender changer.
> 
> Right now I'm still trying to catch up with what I had working before.  
> My ColecoVision RPG is ported over to the same state as it was before, 
> except that I still need to port over the Coleco sound routines.  I 
> updated my assembler so that I could mix code from different CPUs, so 
> now I can mix the Z80 and 68000 code, and use the Coleco sound routines 
> with minimal changes.  And I've started work on porting my Atari 7800 
> game "Tubes" to the point where I can make the tiles fall and stack up.
> 
>  - Bruce -
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