#garfield Logs

Feb 07 2023

08:47 PM rue_shop3: what bit-mixup makes 0xC3 look like a software interrupt?
08:47 PM rue_shop3: on z80
09:29 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/CPU_instructions.pdf
09:39 PM rue_shop3: I'm working thru it
09:39 PM rue_shop3: the protoboard had a bridge between two pads
09:39 PM rue_shop3: they landed on VCC and D0 of the cpu
09:39 PM rue_shop3: :]
09:41 PM Tom_L: the purple ones?
09:41 PM rue_shop3: no, the pressed paper ones
09:41 PM Tom_L: oh
09:42 PM rue_shop3: they have all sorts of defects all the time
09:42 PM rue_shop3: drills that miss
09:42 PM rue_shop3: holes the blob toethor
09:42 PM rue_shop3: plugged holes
09:42 PM rue_shop3: I _LOVE_ NVRAM chips
09:43 PM Tom_L: no refresh required?
09:43 PM rue_shop3: no write limit
09:43 PM rue_shop3: your program can use it as ram
09:43 PM rue_shop3: thats ok,it is
09:44 PM rue_shop3: so program vs ram space is wherever you want
09:47 PM Tom_L: gettin caught up on your sprayer heads?
09:48 PM rue_shop3: the first A9/10 was a bit thick (1/5mm) adjusted, the second one is 1mm, which is max
09:49 PM rue_shop3: 3Hrs 20 mins ea...
09:49 PM Tom_L: on the ring?
09:49 PM rue_shop3: yep
09:50 PM rue_shop3: I need to find an example of a maskable interrupt handler for a z80
09:50 PM Tom_L: that's alot of time
09:51 PM rue_shop3: yea it just runs
09:51 PM Tom_L: https://www.smspower.org/Development/InterruptMechanism
09:52 PM rue_shop3: I'm using mode 1
09:52 PM rue_shop3: ok I _DO_ have to re-enable the interrupts
09:52 PM rue_shop3: but
09:52 PM rue_shop3: I'm getting a funny interrupt-bounce
09:53 PM rue_shop3: maybe my /INT pulse is too long...
09:54 PM rue_shop3: hmm
09:54 PM Tom_L: https://z80journal.wordpress.com/2015/04/15/z80-interrupts/
09:54 PM Tom_L: An example of a mode 1 routine can be seen below,
09:54 PM rue_shop3: so I'm runnign my chip at almost 5MHz, apparently this is only a 2.5MHz version
09:55 PM rue_shop3: oh, they immediatly disbale them
09:56 PM rue_shop3: no, still does it
09:56 PM rue_shop3: hmmm
09:57 PM rue_shop3: INT:
09:57 PM rue_shop3: di
09:57 PM rue_shop3: out (0x01), a
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: nop
09:57 PM rue_shop3: ei
09:57 PM rue_shop3: reti
10:02 PM rue_shop3: huh
10:02 PM rue_shop3: well this sure is being uncopertive
10:02 PM rue_shop3: maybe its becasue the pulse is longer than 1 cycle
10:02 PM rue_shop3: but
10:03 PM Tom_L: bed.. early day ahead
10:04 PM rue_shop3: I'll be back to work "soon"
10:06 PM rue_shop3: oh,
10:06 PM rue_shop3: wtf
10:06 PM rue_shop3: its not my code generating an extra pulse
10:06 PM rue_shop3: ahaha
10:07 PM rue_shop3: the z80 does the dummy read from the io bus
10:07 PM rue_shop3: in a different mode it would be reading a byte to work out where to jump
10:07 PM rue_shop3: they do the read anyhow
10:42 PM rue_shop3: tom how much extra speed does your mist cooler add?
11:17 PM rue_shop3: starting the 4th part today