#garfield Logs
Aug 29 2021
#garfield Calendar
12:04 AM Tom_L: ok, i'm out.
12:12 AM rue_shop3: oh, and the plasma cutter
12:12 AM rue_shop3: gnight
12:12 AM Tom_L: you seem to have some momentum going on this now
12:12 AM Tom_L: keep it going :)
12:12 AM rue_shop3: hah, my projects need more mass
12:13 AM rue_mohr: I'v never put a 8048 and 8051 side by side
12:14 AM rue_mohr: 8021 8022 8039 8048 80C39 80C48 8041
12:14 AM rue_mohr: 8042
12:15 AM rue_mohr: the assembler I'm using for the 8051 supports it
12:15 AM rue_mohr: interesting
12:18 AM Tom_L: later..
12:23 AM rue_mohr: heh, you sleep I'll see you in the morning
12:23 AM rue_mohr: hahah it supports the 4004 too
12:24 AM rue_mohr: thats just cheeky
01:51 AM rue_mohr: 8048 has no serial
02:18 AM rue_mohr: the 8048 only has a 11 bit program counter
02:54 AM rue_mohr: hahah the stack is only 8 words deep so it uses a 3 bit pointer that lives in the status register
03:01 AM rue_mohr: wait
03:01 AM rue_mohr: the stack pointer is part of the data pushed on the stack during a call....
03:02 AM rue_mohr: er, no
03:02 AM rue_mohr: I misread that
03:02 AM rue_mohr: this processor is halarious
03:03 AM rue_mohr: its not much more than a turring machine
03:39 AM rue_mohr: a stack and interrupts were amazing
03:39 AM rue_mohr: this was too close to the beggining of computing
03:41 AM rue_mohr: ok I think I have a valid 8048 program
04:30 AM rue_mohr: haha! I got it!
04:49 AM rue_mohr: morning polprog
04:56 AM rue_shop3: so, the 8035 is working, I'm gonna call it a night
05:24 AM polprog: hey rue
05:25 AM polprog: gotta finish painting sis' room today
05:25 AM polprog: maybe i will try to get the z80 running
05:29 AM polprog: i wonder if sdcc supports 8048
05:29 AM Tom_L: morning
05:30 AM polprog: i have an uv eraseable d8748, but my programmer does not suppport it
08:52 AM aandrew: polprog: I'm rather disappointed in you for not having done this already: https://hackaday.com/2021/08/28/irc-server-for-ms-dos/
08:52 AM aandrew: however you've been more than forgiven for your MS Teams for DOS tweet
08:53 AM aandrew: that was so good in so many bad ways
11:32 AM rue_bed: polprog, 8048 no C!
11:32 AM rue_bed: polprog, EA
11:33 AM rue_bed: ms teams for dos.... huh, I dont recall that one..
12:06 PM rue_mohr: it might be another ok day for casting, I wonder if I can make that template up in time
12:07 PM polprog: rue_bed: hmm, right, but i still dont have a compiler for it
12:09 PM polprog: rue_goose
12:10 PM * polprog is listening to steppenwolf
12:11 PM rue_mohr: there is an assembler
12:11 PM rue_mohr: called as :/
12:11 PM rue_mohr: somehow I have it installed as "asl"
12:11 PM rue_mohr: but I dont see a package for it
12:11 PM rue_mohr: I have source code tho
12:12 PM polprog: hmm
12:12 PM rue_mohr: asl-1.41r8
12:13 PM rue_mohr: Einrueckung fuer 'R' in Retracted-Zeilen im Listing
12:13 PM rue_mohr: see if we can find a tag by google
12:14 PM rue_mohr: only 1 hit
12:14 PM rue_mohr: http://git.osmocom.org/dect/asl/diff/?id=1f3e92989e4b9f3e00aaf7729b3dd2f7c044667e
12:15 PM polprog: of all the projects, i didnt expect osmocom to have that
12:15 PM rue_mohr: whats osmocom
12:16 PM rue_mohr: its the only hit for the source clip I grabbed
12:16 PM rue_mohr: oh, different line
12:17 PM rue_mohr: https://github.com/begoon/asl
12:22 PM rue_mohr: its funny that the 8048 board has a 64k chip, but they put one of the address lines on a select switch, and if the 8048 tries REALLY HARD it can change the 11th address bit
12:23 PM rue_mohr: the manual reads like they were teaching people to use the 8048 that had almost 0 computer experience
12:23 PM rue_mohr: "program is a list of instructions, write out the list of instructions you wish the processor to perform"
12:24 PM rue_mohr: 8-|
12:24 PM rue_mohr: they hand assemble everything
12:24 PM polprog: thats the worst
12:28 PM rue_mohr: this winter I'm gonna clean up my room
12:28 PM rue_mohr: getting a bit much dust in the corners, and the cables could use a massage
12:32 PM polprog: finished painting the sisters room today
12:32 PM rue_mohr: ah good show
12:33 PM rue_mohr: now we program 1980 microcontrollers?
12:33 PM rue_mohr: :)
12:33 PM rue_mohr: how about a python engine?
12:33 PM polprog: later today :)
12:33 PM polprog: gotta organize people for the boat trip
12:33 PM polprog: they nede to tell me what they wanna eat
12:33 PM rue_mohr: realtime python on a 8048
12:33 PM polprog: lol
12:35 PM rue_mohr: there are so many things about this BASIC that dont make sense
12:35 PM rue_mohr: they have a whole file for external rom programming, but then they have a utility function in the main code for ti
12:35 PM rue_mohr: it
12:35 PM rue_mohr: wtf?
12:36 PM rue_mohr: maybe this whole thing is a pile of hacks
12:38 PM rue_mohr: maybe I should subscribe to the possability that even the orig source is a complete illegible mess
12:47 PM rue_mohr: R4B0
12:47 PM rue_mohr: ahaha
12:47 PM rue_mohr: Register 4
12:48 PM rue_mohr: bank 0
12:48 PM rue_mohr: cause, there are two register 4s
12:51 PM rue_mohr: LJMP 2068H
12:51 PM rue_mohr: seriously????
12:51 PM rue_mohr: ohh, right, fixed position user routines
12:51 PM rue_mohr: its 2000+
01:06 PM rue_mohr: interesting
01:06 PM rue_mohr: a grep on "orig" source
01:06 PM rue_mohr: ; The statement action routine - CLEAR
01:06 PM rue_mohr: ; The statement action routine - LET
01:06 PM rue_mohr: ; The statement action routine FOR
01:06 PM rue_mohr: ; The statement action routines - PUSH and POP
01:06 PM rue_mohr: ; The statement action routine - IF
01:06 PM rue_mohr: ; The statement action routine - GOTO
01:06 PM rue_mohr: ; The statement action routines WHILE and UNTIL
01:06 PM rue_mohr: ; The statement action routine - RETI
01:06 PM rue_mohr: ; The statement action routine - RETURN
01:07 PM rue_mohr: ; The statement action routine - GOSUB
01:07 PM rue_mohr: ; The statement action routine - NEXT
01:07 PM rue_mohr: ; The statement action routine - RESTORE
01:07 PM rue_mohr: ; The statement action routine - READ
01:07 PM rue_mohr: ; The statement action routine - PRINT
01:07 PM rue_mohr: ; The statement action routine - INPUT
01:07 PM rue_mohr: ; The statement action routine - CLOCK
01:07 PM rue_mohr: ^^ what stands out to you here?
01:09 PM rue_mohr: this code is organize like 52 pickup
01:09 PM rue_mohr: but its got the fingerprints of havning been quite orderly at some point
01:11 PM Tom_L: <rue_mohr> now we program 1980 microcontrollers.... now that's what i call real progress!
01:12 PM Tom_L: 16 yrs to the day New Orleans is getting hammered again
01:12 PM Tom_L: https://earth.nullschool.net/#current/wind/surface/level/orthographic=-91.15,28.55,5883/loc=-89.469,28.973
01:12 PM rue_mohr: ?
01:12 PM rue_mohr: broser crashed
01:13 PM * Tom_L gives rue_mohr a shiney new uptodate brouser
01:13 PM Tom_L: ~125mph sustained winds
01:13 PM Tom_L: hurricane
01:13 PM rue_mohr: oooh
01:13 PM rue_mohr: thoguht it might be a solar flare
01:14 PM Tom_L: wind map
01:14 PM rue_mohr: SCALL: ; Call a user rountine
01:14 PM rue_mohr: that should say something like "The statement action routine - CALL"
01:15 PM rue_mohr: so its not origional
01:15 PM rue_mohr: oh it loaded
01:15 PM rue_mohr: right
01:17 PM Tom_L: the map?
01:17 PM Tom_L: you can check anywhere on the globe
01:18 PM rue_mohr: yea I just took at look for what it said here
01:20 PM Tom_L: iirc you can set up ocean currents etc too
02:08 PM rue_mohr: a lot of the code in here makes sense
02:08 PM rue_mohr: things like memory moves, forward and backward for string manipulation
02:16 PM rue_mohr: yes, the layers of edits are delaminating
02:35 PM aandrew: RETI is a little weird for BASIC
02:36 PM rue_mohr: they faked interrupt handlers
02:36 PM aandrew: Tom_L: I read that this one is like once in 250y hurricane for LA
02:36 PM rue_mohr: and DMA
02:36 PM aandrew: rue_mohr: yes, that is what stands out to me :-)
02:36 PM rue_mohr: https://www.dos4ever.com/8031board/8031board.html#appendixB
02:36 PM rue_mohr: at the bottom are the different binaries
02:37 PM rue_mohr: maybe I get to start my reverse engineering again
03:15 PM rue_shop3: oh pffft
03:15 PM rue_shop3: I'm gonna 3d print this
03:17 PM Tom_L: cheating
03:18 PM rue_mohr: oh its being a pain
03:19 PM rue_mohr: and I dont have a thickness planer
03:19 PM rue_mohr: god there are WAY too many things going on at this computer
03:21 PM rue_mohr: hmm do I split this template then?
03:29 PM Tom_L: you be the casting expert here!
03:32 PM rue_mohr: the cad is giving my some better numbers anyhow
03:34 PM rue_mohr: I suppose doing it from wood is kinda limited to crude stuff if I'm not getting into a complex prep
03:46 PM rue_mohr: think I should try to find 3/8" brass keyway to make bushings for the slider with?
03:51 PM Tom_L: need to see more of it before i commit to that but maybe
03:52 PM Tom_L: how smooth can you make the 'bearing' surface?
03:52 PM Tom_L: alum/steel might just gauld
03:53 PM Tom_L: cast iron tends to be more friendly that way
03:54 PM rue_mohr: yea
03:55 PM rue_mohr: I'v seen designs just stuff in brass shimstock
03:55 PM Tom_L: brass/bronze would do ok i'm sure
03:55 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/main.png
03:55 PM rue_mohr: the yellow rect is the 4"x1/4" plate that it slides on
03:55 PM Tom_L: yellow the steel plate?
03:55 PM rue_mohr: the circle is the threaded drive rod
03:55 PM rue_mohr: yes
03:55 PM Tom_L: k
03:56 PM rue_mohr: there are two, that is just the bottom half
03:56 PM Tom_L: so where's the shim adjustment?
03:56 PM rue_mohr: I have to cut the casting and poke it all in
03:56 PM rue_mohr: have you seen how the capliprs work?
03:56 PM rue_mohr: the digital ones?
03:56 PM Tom_L: yeah
03:56 PM Tom_L: the slide you mean?
03:57 PM Tom_L: there's nothing retaining that though
03:57 PM Tom_L: just a piece on the very end
03:58 PM Tom_L: you don't want play in this and need it adjustable
04:03 PM rue_mohr: you put little screws in to hold things, the calipers just use little detents
04:03 PM rue_mohr: I also wonder about 3d printing one
04:04 PM rue_mohr: maybe it would hold enough to mill the metal one
04:04 PM Tom_L: a brass piece on top screwed in place with recessed screws and and adjustable one underneath for tightness would be ok
04:05 PM Tom_L: can you get delrin on a spool?
04:08 PM rue_mohr: not that I know of
04:09 PM Tom_L: you want something oil resistant
04:11 PM rue_mohr: like cintered brass?
04:12 PM rue_mohr: heh, I dropped some into the aluminum, wow, lots of flame!
04:13 PM Tom_L: dropped what in?
04:14 PM rue_mohr: the molten aluminum vat
04:14 PM Tom_L: yes, what did you drop in it?
04:14 PM rue_mohr: cintered brass
04:14 PM Tom_L: oh
04:14 PM Tom_L: yeah it's full of oil
04:14 PM Tom_L: hard as heck to machine too
04:15 PM polprog: ok
04:15 PM polprog: done, ill clean up the desk and see if the z80 wants to execute my program
04:15 PM polprog: ill start easy, with 16 nops and a jum
04:15 PM polprog: jump*
04:18 PM rue_mohr: have it jump in and out of loops above and below address 32, so you can use bit 5 as a flashing led
04:18 PM rue_mohr: (of the address line)
04:19 PM polprog: heh
04:20 PM polprog: so sdcc uses ASxxxx as the assembler
04:21 PM polprog: by Alan R Baldwin
04:21 PM polprog: https://shop-pdp.net/ashtml/
04:22 PM polprog: funny that the hard part now is not writing the program, but finding out the assembler directives for stuff like .org and the like
04:24 PM rue_mohr: yea
04:24 PM rue_mohr: the assembler format is always fun
04:25 PM rue_mohr: you want some tested-known-good z80 stuff from sdcc?
04:25 PM rue_mohr: as a starting point?
04:26 PM rue_mohr: hehre
04:26 PM rue_mohr: http://paste.debian.net/1209583/
04:30 PM polprog: ok..
04:30 PM polprog: just when I got the toolchain OK
04:30 PM polprog: thanks for the listing
04:31 PM rue_mohr: helps to have a template
04:31 PM rue_mohr: even an ugly one like that
04:31 PM rue_mohr: lots of dissassemblers to check results with
04:32 PM polprog: ok, so first 'sdasz80 -o 1_loop.asm' then ' sdldz80 -i 1_loop.rel ' -> this makes 1_loop.ihx which seems OK
04:32 PM polprog: shall we burn it?
04:32 PM rue_mohr: dump the ihex to a bin and dissassemble it to check
04:32 PM rue_mohr: ?
04:32 PM polprog: i can see the ihex is ok. i disassembled it in my head
04:32 PM polprog: its 14 nops and jp 0x0000
04:33 PM rue_mohr: :) heh, ok
04:33 PM polprog: nop is 00, jp is C3 [imm16]
04:33 PM polprog: 0000000000000000000000000000000000000000000000c3
04:33 PM polprog: :P
04:33 PM polprog: ah snap
04:33 PM polprog: i forgot the 0000 immediate :v
04:35 PM rue_mohr: aha! my 8051 basic is version 1.2
04:35 PM rue_mohr: that site helped me fingerprint it
04:35 PM rue_mohr: thats cool
04:35 PM rue_mohr: I wasn't sure
04:37 PM rue_mohr: ok, cool cool
04:39 PM polprog: so this will be the third Random Board that i run my code on
04:39 PM polprog: maybe i should write notes
04:39 PM polprog: find the common patterns
04:40 PM rue_mohr: :)
04:40 PM rue_mohr: rom starts at 0x0000
04:40 PM polprog: yes
04:40 PM rue_mohr: - pattern complete -
04:41 PM rue_mohr: :)
04:41 PM polprog: but not always - bios starts at f000:fff0 for some reason
04:41 PM polprog: x86 bios*
04:41 PM polprog: ;)
04:41 PM rue_mohr: for z80 0x0000 is the boot vector
04:42 PM polprog: that was the word i was looking for
04:42 PM rue_mohr: bascialyl the first thing I attacked with the 8048 was, what are the vectors
04:42 PM rue_mohr: reset and interrupts
04:42 PM polprog: hmm
04:42 PM rue_mohr: then I created a .asm file with the .org for those three
04:42 PM rue_mohr: and proceeded to try to work out how to write asm for that assembler
04:42 PM polprog: i wonder if i should write in singular (you) or plural form (we)
04:42 PM rue_mohr: :)
04:43 PM rue_mohr: ?
04:43 PM rue_mohr: I have a translation layer, it kinda all comes out the same
04:43 PM polprog: im writing notes and im wondering whether i should write "we have" "we write a program" or "you have" "you write a program"
04:48 PM polprog: strange
04:49 PM polprog: i just noticed my test bios has .org 0x1fff0 not 0xffff0
04:49 PM polprog: why is that
04:51 PM polprog: i think i remember
04:52 PM polprog: i disassembled some bios and somehow saw that the entry point maps like that but i dont know why
04:52 PM aandrew: heh I do the samet hing
04:52 PM aandrew: between i/me and you and we
04:52 PM aandrew: it's like my handwriting... it's some amalgamation of cursive, printing and block capitals and switches as the sentence is written
04:53 PM Tom_L: i speak fluent gibberish
04:55 PM polprog: i think that might have something to do with how the ROM is mapped
04:56 PM polprog: The offset to the BIOS entry point, in isa-bios range, is 0x1fff0. This means that 0xffff0 (0xe0000 + 0x1fff0) is an emu-phy-address within the isa-bus range that maps to the same host address than 0xfffffff0:
04:58 PM polprog: ISA bios rom is mapped at 0xE0000. E0000 + 1FFF0 = FFFF0 !
05:06 PM aandrew: when I discoverd x86 segment:offset aliasing it was like I'd been handed the rosetta stone
05:07 PM polprog: heh
05:07 PM polprog: more like a pandoras box
05:13 PM polprog: snap
05:13 PM polprog: im out of 28 pin flash roms
05:14 PM polprog: ok, i have two blank 27c512 s
05:20 PM polprog: 52G6928 COPR IBM
05:20 PM polprog: random 27c512
05:21 PM polprog: thats an IBM part#, this looks up as a bios for a 52G8770 system board
05:21 PM polprog: which is an IBM valuepoint bios
05:29 PM rue_shop3: polprog, it is hard when you working on a 8086 and z80 at the same time
05:43 PM rue_shop3: kinda itching to play with the 8048 more
05:43 PM rue_shop3: I should design more casting templates first
05:43 PM polprog: hmm
05:43 PM polprog: i got the board running
05:43 PM polprog: but it keeps resetting itself
05:43 PM rue_shop3: 2U is a nice device size eh?
05:43 PM rue_shop3: polprog, the x86 or the z80?
05:43 PM polprog: and the code seems off, i see activity on all address lines
05:43 PM polprog: x80
05:43 PM polprog: er
05:43 PM polprog: z80
05:43 PM rue_shop3: watchdog hardware
05:44 PM rue_shop3: do you know whats hooked up to the reset line?
05:44 PM polprog: i see actvity up to A6
05:44 PM polprog: right
05:44 PM polprog: reset line
05:44 PM rue_shop3: A6!?
05:44 PM rue_shop3: do a binary dump and check the rom...
05:45 PM rue_shop3: unless maybe something put in a bunch of reset vectors?
05:45 PM polprog: yeah something keeps dropping the reset line
05:45 PM polprog: i have to see the vector table of the z84c0006
05:45 PM rue_shop2: watchdog
05:45 PM rue_shop2: maybe a chip
05:45 PM rue_shop2: maybe a 555
05:46 PM polprog: no 555s detected
05:46 PM rue_shop2: was it in a high reliability system?
05:46 PM rue_shop2: medical or something?
05:46 PM polprog: yeah
05:46 PM rue_shop2: yea, watchdog
05:46 PM polprog: its from medical kit
05:46 PM rue_shop2: for sure
05:46 PM rue_shop2: cut the reset trace and put an RC on iy
05:46 PM rue_shop2: it
05:47 PM rue_shop2: mine was out of a fire alarm, so yea
05:47 PM polprog: though my code is 16 bytes... a6 should be hi all time
05:47 PM rue_shop2: A rack unit (abbreviated U or RU) is a unit of measure defined as 1+3⁄4 inches (44.45 mm)
05:47 PM polprog: a-ha!
05:47 PM polprog: MAX691CPE is next to the CPU
05:47 PM rue_shop2: what that
05:47 PM polprog: Microprocessor Supervisory Circuits
05:47 PM rue_shop2: bingo
05:48 PM polprog: so i have to find out where the WDI line goes
05:48 PM polprog: probably to one of the PIOs
05:48 PM polprog: the timeout is 1 sec
05:48 PM rue_shop2: ...is it in a socket?
05:48 PM polprog: nope
05:48 PM rue_shop2: *oops* did I just cut its legs off!?
05:49 PM polprog: no dont hurt it
05:50 PM rue_shop2: ...
06:01 PM rue_mohr: jump it to A1
06:01 PM polprog: that was my idea ;0
06:04 PM polprog: ok, works now
06:04 PM polprog: watchdog defetaed
06:04 PM polprog: defeated
06:04 PM polprog: so i cant count apparently
06:04 PM rue_mohr: wrong address line?
06:04 PM polprog: the highest address pin that toggles is a5
06:04 PM polprog: a6 is high
06:05 PM polprog: wait, a6 toggles
06:05 PM polprog: and my code is 14 nops and a jump, 14+3 = 17
06:05 PM polprog: ill shear 2 nops off
06:05 PM polprog: that will be 15
06:06 PM polprog: so a0-a4 ~, a5+ high
06:06 PM polprog: that should
06:06 PM polprog: no that doesnt make sense
06:06 PM polprog: it must be servicing some ISRs or something
06:06 PM Tom_L: man, busy ppl in this channel today :)
06:07 PM rue_shop2: maybe you should put returns on the vectors
06:07 PM rue_shop2: something like 0x10 0x18 0x20 0x28...
06:08 PM polprog: i havent found the vector table yet
06:08 PM rue_shop2: oh
06:08 PM rue_shop2: uh
06:10 PM rue_mohr: they didn't table it out here
06:10 PM rue_mohr: NMI is 0x0066
06:11 PM rue_mohr: maskable, depending on the mode, is 0x0038
06:11 PM polprog: what a spread
06:11 PM polprog: that middle of nowhere in my code :v
06:11 PM polprog: whered you find that?
06:12 PM rue_mohr: I have a zilog manual
06:12 PM rue_mohr: er, mostek
06:12 PM rue_mohr: looking for the software ones
06:13 PM polprog: oh
06:13 PM polprog: what a clever system
06:13 PM rue_mohr: ah, 0x0000 0x0008 0x0010 0x0018 0x0020 0x0028 0x0030 0x0038
06:13 PM polprog: isr address is I register + whatever was on the data line
06:13 PM rue_mohr: yes and no
06:13 PM rue_mohr: one of the modes does that
06:14 PM rue_mohr: I'm using a mode like that to do a software jump table
06:14 PM rue_mohr: caue its faster than calculating and calling
06:14 PM polprog: cool
06:14 PM polprog: whats the default mode?
06:14 PM rue_mohr: when you write to the register, it triggers the interrupt and the value you wrote (7 bits) determins the fn number in a table
06:15 PM rue_mohr: uh
06:16 PM rue_mohr: mode 0 allows the interrupting device to put an instruction on the bus...
06:16 PM rue_mohr: mode 1 is a restart at 0x0038...
06:16 PM rue_mohr: mode 2 is that table thing....
06:17 PM rue_mohr: aha
06:17 PM rue_mohr: mode 0 is default
06:18 PM rue_mohr: lets see if we can find this book
06:18 PM polprog: i found the techncial manual
06:18 PM polprog: 03-0029-01
06:18 PM rue_mohr: "This interrupt is generally reserved for very important"
06:18 PM polprog: so i should set mode 1 and then put a return at 0x38
06:18 PM polprog: reti*
06:20 PM rue_mohr: joy, everyone copied zilogs book exactly
06:20 PM rue_mohr: http://ali.lecturer.pens.ac.id/files/Z80%20CPU%20User%20Manual.pdf
06:21 PM rue_mohr: its not he one I have, but it looks as good if not better
06:22 PM rue_mohr: the z80 has an alternate register set
06:22 PM rue_mohr: it seems that nobody in the early days was sure how to deal with registers during interrupts
06:22 PM rue_mohr: so, zilog made another set
06:22 PM rue_mohr: intel,with the 8085 and 8048 kinda did that too, they have R0 and R1
06:22 PM rue_mohr: (register sets)
06:23 PM polprog: ok, so there are IM 0, IM 1 and IM 2 instructions
06:23 PM polprog: ill do IM 1
06:23 PM rue_mohr: oh just leave interrupts disabled
06:23 PM rue_mohr: but put a return at 0x66 :)
06:23 PM polprog: so di?
06:23 PM polprog: whats 0x66 then :D
06:23 PM rue_mohr: if you like, I think they are disabled at reset
06:23 PM rue_mohr: so maybe its a NMI
06:24 PM polprog: ill check the nmi pin
06:24 PM rue_mohr: might be atimer
06:25 PM rue_mohr: ooh!
06:25 PM polprog: lol NMI is kept low
06:25 PM polprog: its an active low pin >_>
06:25 PM rue_mohr: also, z80 has a memory refresh system
06:25 PM rue_mohr: which will keep up to A7 active
06:25 PM rue_mohr: er, A6
06:25 PM rue_mohr: caue its a 7 bit count
06:25 PM rue_mohr: opage 24 of that doc
06:26 PM rue_mohr: it puts a count on it while its doing internal things
06:26 PM rue_mohr: for dram refresh
06:26 PM rue_mohr: and scanning rues keyboard :)
06:26 PM polprog: ok
06:26 PM polprog: still, something keeps NMI low
06:27 PM rue_mohr: low!?
06:27 PM polprog: low
06:27 PM rue_mohr: there is a hardware flag that doesn't get cleared to tell it to piss off
06:27 PM rue_mohr: oh I'm supposed to trim treess...
06:28 PM polprog: whats the instruction to piss off?
06:28 PM polprog: retn!
06:31 PM rue_mohr: reti?
06:31 PM rue_mohr: RETI
06:31 PM rue_mohr: Operation: Return from Interrupt
06:31 PM rue_mohr: page 238
06:31 PM rue_mohr: 283
06:32 PM polprog: reti is for maskable
06:32 PM polprog: retn for nonmaskable
06:32 PM rue_mohr: ah
06:32 PM rue_mohr: good catch
06:37 PM polprog: still, the NMI is held low
06:37 PM polprog: i think ill go to sleep soon
06:40 PM polprog: lol, NMI# is tied to ground
06:41 PM polprog: ok, enough for today
06:44 PM polprog: goodnight
07:16 PM rue_shop3: that seems odd
07:16 PM rue_shop3: should it be pullup high then?
07:20 PM Tom_itx is now known as Tom_L
07:20 PM rue_mohr: I wonder
07:20 PM rue_mohr: I wonder if that effectivley moves the boot to 0x66
10:13 PM rue_shop3: the 8042 is giving me some play
10:30 PM rue_mohr: they moved the multiplexed data bus
10:30 PM rue_mohr: but there is no read strobe it seems
10:31 PM rue_mohr: whoa, what
10:31 PM rue_mohr: they didn't mux it?
10:33 PM rue_mohr: https://cdn.hackaday.io/images/4161251540733428282.png
11:03 PM rue_mohr: I'm starting to think the 8042 isn't as much like the 8048 as I thought
11:07 PM rue_mohr: it compiles the same
11:07 PM rue_mohr: hmmmmmm
11:08 PM rue_mohr: the external memory interface is completely different
11:52 PM rue_shop3: the 8042s wont go
11:53 PM rue_shop3: tommorow, if I have time, I'll try locking the data bus into a NOP and see what the pins are doing
11:53 PM rue_shop3: there are things that dont add up here