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      using Manic Miner and Jet Set Willy game engines

 

 

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Message: 4399

Author: john_elliott_uk

Date: 20/08/2004

Subject: Re: Patch Vectors

 

In manicminerandjetsetwilly@yahoogroups.com, I wrote:

vector: ld hl,tick ;HL = address of the tick count.
inc (hl) ;Add 1 to the count.
ld a,(hl) ;Get its new value
cp 26 ;Or however many ticks you want
ret c ;If A is less than 26, return.
ld (hl),0 ;Reset the counter to 0.
ld hl,80D6h ;HL = address of the conveyor direction
ld a,(hl) ;A = current conveyor flag
xor 1 ;If A was 1, it becomes 0, and vice versa.
ld (hl),a
ret

- Though in JSW64, that only reverses the conveyor animation. To
reverse the conveyor direction, you have to do the same trick to the
correct entry in the element map at 8D33h. Say your conveyor is cell 5
- the entry to reverse is at 8D33h + 2*5 + 1 = 8D3Eh.

 

 

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