Help with timings!

[socram8888]

I'm working on a "custom LAKABAJO" using World Cup Italia '90, a very cheap and easy to get cartridge

I already have the Genesis-side GameGenie codes, and they work (at least on Gens KMod)

I'm using the same cable as the LAKABAJO, with the following PC-side program:

dim shared baseaddr as uinteger
dim count as uinteger
dim curbyte as ubyte

const START_ADDR = &hFFFF4C
const END_ADDR = &hFFFFFF

function readStatus() as ubyte
   return inp(baseaddr + 1) and &hF8
end function

function send(dat as ubyte) as ubyte
   out baseaddr, (dat xor &hFF)
end function

baseaddr = 888

send(&H80)

while not bit(readStatus(), 5) ' WAIT FOR WORLD CUP ITALIA STARTUP (GameGenie puts bit 5 low)
   sleep 1
wend

open "test.bin" for binary access read as #1

   while not bit(readStatus(), 6) ' bypass first read
   wend
   while bit(readStatus(), 6)
   wend

count = 1
while count <= END_ADDR - START_ADDR
   print count
   get #1, , curbyte
   send(curbyte)
   while not bit(readStatus(), 6) ' Wait until SEL goes low
   wend
   while bit(readStatus(), 6) ' Wait until SEL goes high
   wend
   count += 1
wend

print "Finished!"
sleep


It's BASIC (well, not BASIC, but FreeBASIC), so I think it's pretty easy to understood. Ask if you found anything that you don't understood

The problem is that I'm getting 90 "reads", but it should read 180 (exactly the double)

Anyone knows where the problem is?

Thank you in advance

EDIT: I already fixed it. I were using bit 6 as SELECT line, when the SELECT line is actually bit 5 ;D

[Tiido]

no idea...

Try

FOR i% = 0 to END_ADDR - START_ADDR
.....
NEXT i%

perhaps it makes a difference...?

EDIT: did not notice the EDIT

[socram8888]

I still don't work

Anyway, I'm bidding for a faulty MegaCD model 1 for 24$ shipping fees included . I think it should be easy to fix the jammed tray...

[oompa loompa]

Doesn't the original LAKABAJO work?

You need to use C language to write the host program because it is VERY timing sensitive.

Or I can try to include this game into my host program. I only do this if there are enough Game Genie codes . There must be a Game Genie code to modify the horizontal interrupt vector, or else the World Cup game is useless

[Tiido]

FreeBASIC is more or less as fast as C is from what I've been told.

[TheMVRules]

It isn't so very fast on my computer, at least.

[oompa loompa]

I dunno about Freebasic - I've only heard about it. Just try a very short experiment in C. I'm just assuming that C (Visual C++, MINGW, Linux, etc) is a more programmer controlled environment compared to Freebasic

For this LAKABAJO application, your host code needs to be very fast

[Syniphas]

FreeBASIC is as fast as C, because, contrary to popular belief, it's compiled and not interpreted (like the original BASIC language, in the 60's)

Although, I have no idea how the LAKABAJO works, so I can't help you :/

[Tom Maneiro]

Why not screw the whole high-level thing and do coding in assembly?

Or play with those evil compiler optimizer flags - fun fun

[TheMVRules]

Yeah, assembly!

[Tiido]

I love how you can do inline ASM in FB