Actually, the ST did have a blitter but it was shockingly slow. It took so
long to set it up for one blit that it was simply quicker to use the CPU to
do the blitting. So the blitter went unused in all our games
croudyj wrote:Hello everyone,
I just thought I'd respond to the comments about my attitude towards the ST and its blitter. First, I'd like to mention that the operating system was never involved in any of my games on the 8 or 16 bit Ataris. The first few lines of code in the game switched the OS off and took over the whole machine. It was too slow to do it any other way.
When I write about this stuff, I'm just writing it as I remember it. I'll admit that my memory is very faded and sometimes plays tricks on me. I'm talking about 1987-1990 which is so long ago it feels like another lifetime. What I do remember about the ST's blitter was that I couldn't figure it out on my own and got Ronald Pieket to help me. I don't remember how we approached it, but it's very possible that we did something wrong. All I remember was that we looked at each other in horror when we saw the results of using the blitter. I think the results were ever so slightly faster than the CPU, but not enough to make it worth bothering with. Like I said, we may have done something wrong. If the blitter was better than I thought, it's a real shame I didn't know how to use it.
You're right, I don't like the ST, but on thinking about that I realise that it's not really the machine's fault. Programming at that time could be very frustrating because it was so difficult to get information. Since there was no Internet, I was at the mercy of any books I could find. I only had a few ST books and they were very bad. One was an awful translation from German and written by a guy who clearly didn't understand the 68000 very well. If I couldn't figure it out, or find anyone who knew the answer, all was lost. It's this frustration that has coloured my memory and feelings towards the machine in a negative way. I don't have those bad feelings towards the Atari 8-bits or the Amiga because I was able to get my hands on excellent documentation for both.
croudyj wrote:I'm devastated! My apologies for letting the Atari community down. I had no idea that my games could have been so much faster. Looks like I really messed up there. Perhaps I should have made more effort to get proper docs. On that day when I decided the blitter wasn't worth the trouble, I did wonder why on earth they would have designed it so badly. Now I wish I had looked into it further.
All I remember now is the frustration I felt. I used to call up book shops to try and see if they had something in stock that I could use. I usually ended up browsing the shelves desperately looking for something. I remember the day I heard about the 8-bit book "De Re Atari". It was only by chance I saw it in the window of a computer shop. I jumped on it. It was £25 just for the unbound sheets of paper. That was pretty expensive for a book in 1982 but I had to have it. Without that book I would never have been able to do anything good on the 8-bit machines. Prior to that I had been relying on gems from magazine articles!
Well... I'm truly sorry. What a fail
lostdragon wrote:John's views are of course his own personal ones and based on his experience working on the hardware itself.
Anything that encourages debate i personally welcome with these interviews, I.D's Dave Taylor's had a similar reaction amongst the Atari community.
My 'plans' for interviews in 2015 are to tread a different path, as along with the 3 interviews which will appear in ST Gamer Vol 2, i'm now supplying interviews for 2 'publications' along side ST Gamer.
1 another Digital Only affair, the other a physical print magazine.More details once the 1st interviews go 'live' in said magazines.
dma wrote:Thanks for your work on those games conversions, it seems i played to all those you took part in.
Especially Silkworm, with its great and indeed arcade faithful gameplay.
Also someone who built a homemade analog synth is automatically a great person.
lotek_style wrote:John: I wonder... there are a couple of chipmusics in the ASMA Atari 8bit music archive... they are credited to you with a questionmark... can you confirm that you did these musics too?
Asteroidz and Munching Mandy
Frank B wrote:Excluding set up time it takes 6 bus cycles (24 cpu cycles) to mask and shift a 16 bit word on the screen
leonard wrote:Frank B wrote:Excluding set up time it takes 6 bus cycles (24 cpu cycles) to mask and shift a 16 bit word on the screen
Could you elaborate on this? I'm not a blitter expert but it seems quite fast. If it takes 6 bus cycles for 1 bitplan, 16 pixels, it takes 24 for 4 bitplans. A complete 4 bitplan screen is 20*200*24 = 96000 bus cycles, which means more than twice a PAL 50Hz frame. (PAL frame is 313*128=40064 bus cycles). Did I miss something?
On the other hand, when you say "mask", you mean a generic mask pattern (read from memory?) (and not the two end masks that you can't setup for each line of the sprite?).
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