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Re: Component Advice Please?
Posted: Sat May 17, 2025 8:29 am
by t0nyt
Arleybls wrote: Fri May 16, 2025 7:42 pm
I am afraid that will not do any good given the socket type on the QL is not hollow (at least on mine
) SO you would have to change the socket first to create space
Well the PCB won’t be sitting flush on top of the socket because of the plastic spacers on the legs and the centre of the QL socket is slightly lower than the edges.
I’ve compared dimensions with one of Chr$ ROM boards (which fit fine) and my measurements suggest it should fit
Only one way to be sure though!
The thing that really confuses me though is that the pictures of original boards I’ve seen are socketed!
Re: Component Advice Please?
Posted: Sat May 17, 2025 9:05 am
by t0nyt
I just tried bending the pins on a similar (spare) IC and it worked without any breaks
I then did a dry fit (along with EEPROM & QL socket legs) which shows just a bit of trimming on 74LS133 legs (under EEPROM) & one set of QL legs will allow all the parts to fit snuggly to the board
It comes out at the same height as one of Chr$ ROM boards and 74LS133 won’t need any space in QL ROM Socket
The big question is whether I can do it for real!
Re: Component Advice Please?
Posted: Sat May 17, 2025 4:32 pm
by t0nyt
Decided to give it a go and see how I got on (haven't checked the soldering yet!)
All sockets removed and the 74LS133 is now upside down underneath (I didn't have any problems bending all the pins upwards). I can't see any reason why this wouldn't fit inside a QL height wise now, though yet to try it
Only tested it as a ROM and RTC, but all seems good
The top of the 74LS133 sits lower than the plastic collars of the QL legs so can't foul the QL socket
Edit: when I say “top” it’s actually the bottom of course
- IMG_4768.jpeg (49.04 KiB) Viewed 417 times
Re: Component Advice Please?
Posted: Mon May 19, 2025 11:27 am
by t0nyt
I kept getting "xmit error" with i2c and now both boards also give that error when trying to set the time, or settings, as well using miniconfig_bas
Have decided to give up on this. At least I've had some soldering practice!
Many thanks
Re: Component Advice Please?
Posted: Mon May 19, 2025 11:36 am
by javier2112
Arleybls wrote: Thu May 15, 2025 7:42 pm
It looks very nice! Have you published your solution? It'd be very helpful for other users.
Haven't published yet, still need to test the i2c as well. The battery holder fits a cr927, I am yet to see if the timekeeper current req of the smd pcf will make this a usuable solution.
That said, i can ofc share the gerbers if someone is also willing to test this (schematics is pretty much the same as the original). Just drop me a msg.
Thanks Arleybls for your offer, but unfortunetly, my only QL has just died
As soon as I have the chance, I'll start a thread about it .
Re: Component Advice Please?
Posted: Mon May 19, 2025 11:48 am
by t0nyt
I just had an epiphany
I put the socket less board inside of the QL instead of attached to the external ribbon cable (it fits inside ok, but I’ll need to remove the battery connector pins and solder the battery leads directly to the PCB)
Now the miniconfig_bas is working fine again
My program to control the LCD spectacularly crashes the QL, but it doesn’t error so I’ll revisit this when I can find some more time
Many thanks
Re: Component Advice Please?
Posted: Tue May 20, 2025 10:25 am
by t0nyt
Am happy to report I've finally got the LCD working with the I2c interface, so definitely working on the mk2 remake
It's very simple test code (wasn't that simple to get it working though as it turned out, but that was down to my lack of understanding) but credit needs to go to MartinB on stardot for the original BBC code
Code: Select all
30 PROC_INIT
40 DIM M$(40) : M$="SINCLAIR QL Minerva v1.98 Mk2"
50 FOR C=1 TO LEN(M$)
60 D$=M$(C TO C)
70 C%=CODE(D$)
80 H%=(C% && HEX('F0')) || HEX('09')
90 L%=((C%*16) && HEX('F0')) || HEX('09')
100 D%=H%:I2CTXB(D%) : REMark *I2CTXB 3F D%
110 PROC_EN
120 D%=L%:I2CTXB(D%) : REMark *I2CTXB 3F D%
130 PROC_EN
140 NEXT C
150 STOP
160 DEFine PROCedure PROC_INIT
170 DATA HEX('38'),HEX('38'),HEX('38'),HEX('28'),HEX('28'),HEX('88')
175 DATA HEX('08'),HEX('88'),HEX('08'),HEX('18'),HEX('08'),HEX('68')
180 DATA HEX('08'),HEX('E8'),HEX('88'),HEX('08')
190 RESTORE 170
200 FOR D=0 TO 15
210 READ D%
220 I2CTXB(D%) : REMark *I2CTXB 3F D%
230 PROC_EN
240 NEXT D
250 END DEFine
260 DEFine PROCedure PROC_EN
270 D%=D% || HEX('04')
280 I2CTXB(D%) : REMark *I2CTXB 3F D%
290 D%=D% && HEX('FB')
300 I2CTXB(D%) : REMark *I2CTXB 3F D%
310 END DEFine
500 DEFine PROCedure I2CTXB(D%)
510 LOCal r$
520 r$=I2C_IO(CHR$(164) & CHR$(D%) & CHR$(255),0,HEX('27'),1)
530 END DEFine
Many thanks all for the various advise
Re: Component Advice Please?
Posted: Tue May 20, 2025 10:47 am
by techy
nice result !!
Re: Component Advice Please?
Posted: Tue May 20, 2025 12:14 pm
by Derek_Stewart
t0nyt wrote: Tue May 20, 2025 10:25 am
Am happy to report I've finally got the LCD working with the I2c interface, so definitely working on the mk2 remake
IMG_4779.jpeg
Hi Tony,
What is the make of the LCD?
Re: Component Advice Please?
Posted: Tue May 20, 2025 12:27 pm
by t0nyt
Derek_Stewart wrote: Tue May 20, 2025 12:14 pm
t0nyt wrote: Tue May 20, 2025 10:25 am
Am happy to report I've finally got the LCD working with the I2c interface, so definitely working on the mk2 remake
IMG_4779.jpeg
Hi Tony,
What is the make of the LCD?
Hi Derek,
There's no identifying marks on it that I can find, but the eBay seller has re-listed it
https://www.ebay.co.uk/itm/263042637252 (looks like the same one I purchased)
Mine seems to have a TI version of the PCF8574 I2C control board as it defaults to address $27