#garfield Logs

Dec 08 2023

06:13 AM polprog: rue_mohr: happy birthday :)
07:24 AM rue_mohr: :]
07:24 AM rue_mohr: too many things go numb if I sleep in the chair
07:29 AM Tom_L: happy birthday
07:53 AM rue_mohr: :]
08:43 AM aandrew:
08:54 AM aandrew: oh that's right, it's rue's birthday
08:54 AM aandrew: happy birthday rue_mohr
11:51 AM Felix is now known as OK9UWU
01:16 PM polprog: hi felix
01:16 PM OK9UWU: Hey
01:16 PM polprog: OK9UWU: i wanted to ask which stm32 did you get
01:17 PM polprog: what board
01:17 PM OK9UWU: f401, not sure which subversion, i think the one with maxed RAM and memory
01:17 PM OK9UWU: STM32F401VE
01:18 PM OK9UWU: they are sold as "Blackpills"
01:18 PM polprog: oh these
01:18 PM polprog: f4 are pretty capable
01:18 PM polprog: if you need any help with programming them we can help
01:18 PM polprog: gonna use the STM Cube hal or libopencm3?
01:19 PM OK9UWU: Yeah, i think i'll have a lot of headroom with what i know now and the amount i can learn with these, they have a proper floating point unit so doing some DSP should be easy
01:19 PM OK9UWU: libopencm3 probably, seems a bit more straighforward with debugging
01:23 PM OK9UWU: I'll certainly reach out if i'll get stuck with my progress, thanks. Speaking of which, i finally got a full, nonbroken dump of the Z80 EPROM, i got the dual arduino reader to work but i had to sacrifice on the reading speed. Trying to figure out what to do next with the dump
01:28 PM polprog: well you know it's z80, so you can write your own assembly code and burn a new rom
01:28 PM polprog: if you have an eprom programmer that is
01:28 PM polprog: otherwise, study it
01:29 PM polprog: im not sure if ghidra supports z80 haha
01:29 PM OK9UWU: Yeah, i dont, i'd like to know how to study it, i managed to read some of the instructions from the hex dump (if that makes sense lol) but nothing organised and nothing that would shine light onto the original purpose of this board
01:30 PM polprog: can you post some hi res pics of it? both sides
01:30 PM polprog: it looks like some controller card so there isnt much on it
01:30 PM polprog: and iirc that was not a bare z80 but some z80 based microcontroller
01:31 PM polprog: so that part is nice because it would have all the internal peripherals at a fixed address
01:31 PM polprog: like the 8051
01:31 PM OK9UWU: Yeah let me snap some pics, its IPC so yeah a ton of peripherals in the chip aswell. give me 5mins
01:31 PM polprog: i did something similar with the 8051 and eventually I ran some 8051 monitor program and 8051 basic on it
01:31 PM polprog: sure
01:31 PM polprog: and some other day I will bother you about ham radio and RF stuff haha
01:32 PM polprog: (I enjoyed reading your radio stuff on twitter)
01:32 PM OK9UWU: Mentioning 8051, i have some AT89C55WD, weren't those based on 8051 aswell? Yeah no worries, ask me anything anytime, i'll try to help.
01:34 PM polprog: that sounds like 8051 compatible
01:35 PM polprog: and old enough that most ROM programmers should be happy with it
01:35 PM OK9UWU: I got like 12of them at a hamfest in Northern Bohemia for free, i dont know what to do with them so they are just waiting in the box for the right time-
01:36 PM polprog: heh, same here
01:36 PM polprog: i have a bunch of OTP 8051's, that I bought (literally) a whole bag of
01:36 PM polprog: i think there are 20 of them
01:36 PM polprog: they are programmed but you can force them to run from an external EPROM
01:37 PM polprog: ok so that one you have is has flash memory (good!) and uses the regular programming interface, parallel
01:37 PM polprog: iirc there were some newer at89 series that could be programmed over SPI
01:38 PM OK9UWU: Interesting, i guess that would be the predecessor to ISP then
01:39 PM OK9UWU: https://ibb.co/JcpSRh2
01:39 PM OK9UWU: https://ibb.co/3R67MGv
01:39 PM OK9UWU: https://ibb.co/f19KHV1
01:39 PM OK9UWU: https://ibb.co/5FZXp2n
01:39 PM OK9UWU: https://ibb.co/mGvwq6P
01:39 PM OK9UWU: images
01:40 PM polprog: allrighty
01:40 PM OK9UWU: supposedly, this should not only support RS232 but also RS422 and RS485, I am going to get some pics of the whole mainboard aswell
01:40 PM polprog: so you have the microcontroller, and an external ROM and external RAM
01:40 PM polprog: These two HC00 are going to be on the address lines and decode the address ranges to enable the ROM or RAM
01:40 PM polprog: so thats the first thing to map out, what address lines they decode for the ROM and RAM /OE
01:41 PM polprog: theres also that J1 port which goes somewhere, i dont know the pinout to tell which port is there
01:42 PM OK9UWU: Thats the bus connecting it to the mainboard of the radiomodem this was in, just taking apart the second unit i havent disassembled to show its insides
01:43 PM OK9UWU: There's the serial comms to the outside, receiver squelch line + keying for the transmitter, RX and TX + clock for the GFSK modem.
01:44 PM polprog: that RF can it sits in is nice
01:45 PM polprog: yeah so once you figure out these 74hc00's then you will know the address map
01:45 PM polprog: where the ext ram is and the ext rom is
01:46 PM OK9UWU: also, there seems to be a small SMD eeprom on the top, next to the 78l05, what could that be
01:46 PM OK9UWU: atleast, i assume its eeprom, couldnt find the exact model number online
01:47 PM polprog: i think that might be a reset supervisor chip
01:47 PM polprog: or a watchdog chip
01:47 PM polprog: C46C1 (u5) is some eprom
01:48 PM polprog: U6 is just a 7805 in a funky case
01:48 PM polprog: 78L05 to be precise
01:48 PM OK9UWU: yep
01:52 PM OK9UWU: https://ibb.co/26cjrDB
01:52 PM OK9UWU: https://ibb.co/x7yVDzN
01:53 PM OK9UWU: https://ibb.co/6YxD6mC
01:53 PM OK9UWU: https://ibb.co/D44rM8W
01:54 PM polprog: looks like that header is going to have 5V serial on it
01:55 PM OK9UWU: Yeah, thru the Motorola drivers it goes out as classic RS232 on a DB25 V.24
01:55 PM polprog: yep
01:56 PM OK9UWU: And yes i tried to talk with it over serial, nothing, it returns garbage mostly
01:56 PM OK9UWU: Nothing that would make any sense)
01:57 PM polprog: hm, got the right baudrate?
01:57 PM polprog: if its a modem it should talk like a modem
01:57 PM OK9UWU: Tried from 1200 all the way to 57k6
01:58 PM OK9UWU: Yeah but this one is a bit more smart due to the Z80 microcomputer, it has on air auth, possibility to create private networks etc
01:59 PM polprog: ah this kind of thing
01:59 PM polprog: nice
01:59 PM polprog: i was thinking about getting a ham licence recently
01:59 PM OK9UWU: it was used in infrastructure, water towers, substations, sewer pumping stations, anything that had a computer and was meant to talk to the central command, way before GSM/3G/LTE,talking about early 1990s
02:00 PM OK9UWU: Where are you from by the way? My wild guess would be Poland from your accent?
02:03 PM polprog: you are right
02:03 PM polprog: :)
02:04 PM OK9UWU: Ha! :-D , Getting a HAM license shouldn't be hard then, what i heard from some of my friends there. And afterwards you can mess around with wireless electronics on extreme distances legally.
02:17 PM polprog: thats what i wanna do
02:17 PM polprog: i want to make some mesh network at 433 and other frequencies
02:17 PM polprog: i dont relaly need a licence for 433 but it would be nice to have
02:17 PM polprog: since i uhh
02:17 PM polprog: have a lot of radios i should not technically have
02:17 PM OK9UWU: is it illegal to own such equipment unless you have a license in Poland?
02:28 PM polprog: its a grey area
02:28 PM polprog: its illegal to transmit
02:28 PM OK9UWU: Yeah, but owning=! transmitting
02:29 PM OK9UWU: Here it was illegal to own anything that could transmit without a license until 2004, after that the laws were changed and now its allowed
02:41 PM polprog: bbl
06:24 PM rue_mohr: A15 will be the ram/rom CS line
06:24 PM rue_mohr: ROM 0000-7FFF RAM 8000-FFFF
06:26 PM rue_mohr: I have new seagate boards
06:26 PM rue_mohr: 6 of them
06:27 PM rue_mohr: marvel 88i chips
06:45 PM Tom_L: for something to do i may sw up your tube fixture
06:45 PM Tom_L: what size drill do you think you need for that?
06:45 PM Tom_L: 1"?
06:47 PM Tom_L: and where are that series of pics you did for that?
06:47 PM * Tom_L drops a brick on rue_mohr's toe to get his attention
06:48 PM rue_mohr: bricks? greenhouse!
06:48 PM rue_mohr: wait, what
06:48 PM rue_mohr: I'm just home from work
06:48 PM Tom_L: oh
06:48 PM rue_mohr: I need to drive to a buddys with cake, then go have supper with family
06:48 PM Tom_L: it seems later... it gets dark so early
06:49 PM Tom_L: that's on the end with the 2 slots right?
08:15 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/Can_Holder/Tube_slots/Tube_fixture1.JPG
08:15 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/Can_Holder/Tube_slots/Tube_fixture2.JPG
08:15 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/Can_Holder/Tube_slots/Tube_fixture3.JPG
08:18 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/Can_Holder/Tube_slots/Drill_fixture.STL
08:19 PM Tom_L: probably need to adjust for tolerance etc and maybe move the hole
08:20 PM Tom_L: i didn't draw the .125" slot so the hole may need to be moved down so it doesn't cut into it
08:21 PM Tom_L: i moved it a bit since those files so that the hole center is the edge of the tube
08:24 PM Tom_L: and shortened the block some. didn't need to be that long
08:27 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/Can_Holder/Tube_slots/Tube_fixture4.JPG
08:27 PM Tom_L: adjusted size
08:28 PM Tom_L: updated the stl too
08:36 PM Tom_L: made the holes .005" oversize and the slot .005" undersize on the width
11:38 PM rue_mohr: ok I'm back
11:39 PM rue_mohr: Tom_L, ah!
11:39 PM rue_mohr: heh, I can see your polygons