Neat! I like that. Kudos to those who devised that nifty piece of assembly.
I was programming the Signetics 2650 at the time in assembler and BASIC.
Still got that 50 year old processor in a working condition. It made promotion. It went from a 80 x 24 CRT/keyboard controller to a doorbell. 🤪🤣😜😙
I was programming the Signetics 2650 at the time in assembler and BASIC.
Still got that 50 year old processor in a working condition. It made promotion. It went from a 80 x 24 CRT/keyboard controller to a doorbell. 🤪🤣😜😙
November 17, 2025 at 12:41 PM
Neat! I like that. Kudos to those who devised that nifty piece of assembly.
I was programming the Signetics 2650 at the time in assembler and BASIC.
Still got that 50 year old processor in a working condition. It made promotion. It went from a 80 x 24 CRT/keyboard controller to a doorbell. 🤪🤣😜😙
I was programming the Signetics 2650 at the time in assembler and BASIC.
Still got that 50 year old processor in a working condition. It made promotion. It went from a 80 x 24 CRT/keyboard controller to a doorbell. 🤪🤣😜😙
Of course the dating of 1974 and 1976 regarding the APVS are bogus and have been debunked elsewhere, simply because Signetics had not designed the video chip by then and barely even had the CPU ready. 1978 is reasonable though.
November 10, 2025 at 5:42 PM
Of course the dating of 1974 and 1976 regarding the APVS are bogus and have been debunked elsewhere, simply because Signetics had not designed the video chip by then and barely even had the CPU ready. 1978 is reasonable though.
Love this style! Really cute & detailed.
I’d replace the 5200 with an Acetronic or Interton APVS machine, because I think Signetics machines deserve more attention, but that’s just me 🤷♂️🤣
I’d replace the 5200 with an Acetronic or Interton APVS machine, because I think Signetics machines deserve more attention, but that’s just me 🤷♂️🤣
April 4, 2024 at 7:09 PM
Love this style! Really cute & detailed.
I’d replace the 5200 with an Acetronic or Interton APVS machine, because I think Signetics machines deserve more attention, but that’s just me 🤷♂️🤣
I’d replace the 5200 with an Acetronic or Interton APVS machine, because I think Signetics machines deserve more attention, but that’s just me 🤷♂️🤣
The PLS100 is a rebadged Signetics 82S100, which is a bipolar field-programmable logic array (FPLA) that was first released in 1975. It was the first commercially successful programmable logic device. The Commodore 64 used the 82S100/PLS100 as the "PLA" chip, eliminating a ton of discreet ICs.
March 3, 2025 at 11:13 PM
The PLS100 is a rebadged Signetics 82S100, which is a bipolar field-programmable logic array (FPLA) that was first released in 1975. It was the first commercially successful programmable logic device. The Commodore 64 used the 82S100/PLS100 as the "PLA" chip, eliminating a ton of discreet ICs.
My first computer was built in the '70s from TTL logic. It was a 4-bit CPU, programmed by toggle switches. Later I got a Signetics 2650 (CPU) evaluation board and a dumb terminal and made a computer out of it. I wrote a simple editor and one-pass assembler. (pt 1)
November 17, 2024 at 5:49 AM
My first computer was built in the '70s from TTL logic. It was a 4-bit CPU, programmed by toggle switches. Later I got a Signetics 2650 (CPU) evaluation board and a dumb terminal and made a computer out of it. I wrote a simple editor and one-pass assembler. (pt 1)
The Bitsavers archive has images of the three bipolar PROMs of the ZX-203. Two of them, labeled "BM1" and "BM2" are 4K*8 PROMs (e.g. Fujitsu MB7152E), containing the 16-bit-wide firmware that runs on the Signetics 8X305 bipolar processor. The other, labeled "BM1", is a 512*8 PROM (e.g. SN74S472 […]
Original post on mastodon.social
mastodon.social
July 24, 2025 at 2:58 AM
The Bitsavers archive has images of the three bipolar PROMs of the ZX-203. Two of them, labeled "BM1" and "BM2" are 4K*8 PROMs (e.g. Fujitsu MB7152E), containing the 16-bit-wide firmware that runs on the Signetics 8X305 bipolar processor. The other, labeled "BM1", is a 512*8 PROM (e.g. SN74S472 […]
I did a series of Singetics designs around their cool logos. This is an early Signetics µA741 Opamp (originally designed by Fairchild). Basically this model became the canonical opamp, down to the pins, IIRC.
November 13, 2025 at 5:57 PM
I did a series of Singetics designs around their cool logos. This is an early Signetics µA741 Opamp (originally designed by Fairchild). Basically this model became the canonical opamp, down to the pins, IIRC.
The Signetics 8X330 floppy controller chip used on the board has an internal VCO, but the datasheet says that better performance can be had with an external VCO. Sadly, the datasheet does not give an example circuit. Signetics probably published an application note with more details, but there […]
Original post on mastodon.social
mastodon.social
July 24, 2025 at 3:08 AM
The Signetics 8X330 floppy controller chip used on the board has an internal VCO, but the datasheet says that better performance can be had with an external VCO. Sadly, the datasheet does not give an example circuit. Signetics probably published an application note with more details, but there […]
Ok, I'm no expert. We discussed the earlier 1292 APVS era on AtariAge a while ago: which was their origin, which model was first etc and got rather far. Quite possibly Philips, owner of Signetics, put out a reference design for their new chips.
December 2, 2024 at 7:36 PM
Ok, I'm no expert. We discussed the earlier 1292 APVS era on AtariAge a while ago: which was their origin, which model was first etc and got rather far. Quite possibly Philips, owner of Signetics, put out a reference design for their new chips.
Third in a series of vaguely interesting #Signetics #APVS coding tricks is this one that makes game variant selection a bit easier...
If you look at cartridges, you might notice that single player and two player games often alternate:
If you look at cartridges, you might notice that single player and two player games often alternate:
March 30, 2024 at 5:23 PM
Third in a series of vaguely interesting #Signetics #APVS coding tricks is this one that makes game variant selection a bit easier...
If you look at cartridges, you might notice that single player and two player games often alternate:
If you look at cartridges, you might notice that single player and two player games often alternate:
With additional hardware and supporing software, the disk-drive system can be expanded without limit; however, five or six drives is sufficient for most applications.
-- Signetics 8X330 Floppy Disk Formatter/Controller Product Specification, 1986
-- Signetics 8X330 Floppy Disk Formatter/Controller Product Specification, 1986
July 19, 2025 at 8:00 AM
With additional hardware and supporing software, the disk-drive system can be expanded without limit; however, five or six drives is sufficient for most applications.
-- Signetics 8X330 Floppy Disk Formatter/Controller Product Specification, 1986
-- Signetics 8X330 Floppy Disk Formatter/Controller Product Specification, 1986
And we've had this tech since 1972!
October 20, 2025 at 1:44 PM
And we've had this tech since 1972!
You might now spot why the second option is preferable, as the LODI operation takes up two bytes - the LODI instruction and the value to load (i.e. 0) - but EORZ,r0 takes only one.
(Exactly how the Signetics 2650 instruction set fits all the necessary info into a single byte is another story 😜)
(Exactly how the Signetics 2650 instruction set fits all the necessary info into a single byte is another story 😜)
February 15, 2024 at 10:37 AM
You might now spot why the second option is preferable, as the LODI operation takes up two bytes - the LODI instruction and the value to load (i.e. 0) - but EORZ,r0 takes only one.
(Exactly how the Signetics 2650 instruction set fits all the necessary info into a single byte is another story 😜)
(Exactly how the Signetics 2650 instruction set fits all the necessary info into a single byte is another story 😜)
Fandom is built on in-jokes; the number of the #GeneralTechnics suite at #Windycon 51 is one of them.
Room 555 reminds old-timers (heh) of the Signetics NE 555 chip, "an integrated circuit used in a variety of timer, delay, pulse generation, & oscillator applications." (W'pedia)
Back in the 70s…
Room 555 reminds old-timers (heh) of the Signetics NE 555 chip, "an integrated circuit used in a variety of timer, delay, pulse generation, & oscillator applications." (W'pedia)
Back in the 70s…
555 timer IC - Wikipedia
en.wikipedia.org
November 2, 2025 at 8:35 AM
Fandom is built on in-jokes; the number of the #GeneralTechnics suite at #Windycon 51 is one of them.
Room 555 reminds old-timers (heh) of the Signetics NE 555 chip, "an integrated circuit used in a variety of timer, delay, pulse generation, & oscillator applications." (W'pedia)
Back in the 70s…
Room 555 reminds old-timers (heh) of the Signetics NE 555 chip, "an integrated circuit used in a variety of timer, delay, pulse generation, & oscillator applications." (W'pedia)
Back in the 70s…
I’m now fixated on writing a version of Black Box in Signetics 2650 assembler for #APVS1292 systems. I’ve literally spent hours trying to figure out whether it’s possible or not… 🤔🤪
January 18, 2024 at 11:06 AM
I’m now fixated on writing a version of Black Box in Signetics 2650 assembler for #APVS1292 systems. I’ve literally spent hours trying to figure out whether it’s possible or not… 🤔🤪
That's an old Signetics PDIP, they used Novolac epoxy. I don't recall it having fiberglass flakes though.
(I think you may have sanded down an identical chip to decap in 2022...)
(I think you may have sanded down an identical chip to decap in 2022...)
December 9, 2024 at 3:22 AM
That's an old Signetics PDIP, they used Novolac epoxy. I don't recall it having fiberglass flakes though.
(I think you may have sanded down an identical chip to decap in 2022...)
(I think you may have sanded down an identical chip to decap in 2022...)
I made a few plans over Christmas:
1, To make a conscious effort to work through my frankly ridiculous restorations backlog.
2. To do more Signetics 2650 coding.
3. To find somewhere to talk about what I'm doing that isn't X.
So, I'm now here. And will hopefully pop up in a few more places soon 😁🙏
1, To make a conscious effort to work through my frankly ridiculous restorations backlog.
2. To do more Signetics 2650 coding.
3. To find somewhere to talk about what I'm doing that isn't X.
So, I'm now here. And will hopefully pop up in a few more places soon 😁🙏
January 16, 2024 at 12:00 PM
I made a few plans over Christmas:
1, To make a conscious effort to work through my frankly ridiculous restorations backlog.
2. To do more Signetics 2650 coding.
3. To find somewhere to talk about what I'm doing that isn't X.
So, I'm now here. And will hopefully pop up in a few more places soon 😁🙏
1, To make a conscious effort to work through my frankly ridiculous restorations backlog.
2. To do more Signetics 2650 coding.
3. To find somewhere to talk about what I'm doing that isn't X.
So, I'm now here. And will hopefully pop up in a few more places soon 😁🙏
I am thrilled to announce that tomorrow, together with a German research colleague, the founder of the German company Interton will be interviewed for the first time. Will we finally be able to solve the mystery of the family of consoles based on the Signetics 2650+PVI?
February 19, 2025 at 7:51 PM
I am thrilled to announce that tomorrow, together with a German research colleague, the founder of the German company Interton will be interviewed for the first time. Will we finally be able to solve the mystery of the family of consoles based on the Signetics 2650+PVI?
The purpose of these two lines of code is to blank the left and right Score values at the beginning of the game. To do so, they each need to be set to a number greater than 9, as explained in the Signetics 2636 Programmable Video Interface (PVI) manual, here:
February 20, 2024 at 6:28 PM
The purpose of these two lines of code is to blank the left and right Score values at the beginning of the game. To do so, they each need to be set to a number greater than 9, as explained in the Signetics 2636 Programmable Video Interface (PVI) manual, here:
The saga of the Interton VC4000 is over. A client mailed 4 of these consoles to me to mod for use with normal power supplies and composite output, and I can confidently say I know more about the Signetics chipset than I ever thought I would
July 27, 2023 at 7:17 PM
The saga of the Interton VC4000 is over. A client mailed 4 of these consoles to me to mod for use with normal power supplies and composite output, and I can confidently say I know more about the Signetics chipset than I ever thought I would
More recently I've used Python and PyParsing, for tools for e.g. the Signetics 8X300 and Intel 8089. There was a little learning curve on using a Parsing Expression Grammar (PEG) rather than a separate lexer and LALR(1) parser. In some cases, productions have to be done a little differently, but […]
Original post on mastodon.social
mastodon.social
December 16, 2025 at 4:14 AM
More recently I've used Python and PyParsing, for tools for e.g. the Signetics 8X300 and Intel 8089. There was a little learning curve on using a Parsing Expression Grammar (PEG) rather than a separate lexer and LALR(1) parser. In some cases, productions have to be done a little differently, but […]
The Condition Code (CC) is the main mechanism the Signetics 2650 processor uses to compare two values.
March 30, 2024 at 5:32 PM
The Condition Code (CC) is the main mechanism the Signetics 2650 processor uses to compare two values.