Search found 162 matches

by blittled
Wed Oct 18, 2017 1:21 pm
Forum: Welcome Area
Topic: My 1000 is on its way OHIO
Replies: 14
Views: 577

Re: My 1000 is on its way OHIO

Hi from a neighbor in northwestern Pennsylvania :)
by blittled
Fri Aug 11, 2017 4:21 pm
Forum: Welcome Area
Topic: Hello from Colorado USA
Replies: 11
Views: 572

Re: Hello from Colorado USA

Hi craftsman1234, Welcome from another American in Pennsylvania! :) I wonder if OTLA would work on some hardware I have. I used an Arduino Due with a TFT interface to read in from an SD card and convert the p file to 3.3V pulses which are the perfect amplitude for the ZX81. Once I got the timing dow...
by blittled
Wed Jul 26, 2017 8:35 pm
Forum: Hardware
Topic: Difficult to load vs non-working cassettes
Replies: 10
Views: 303

Re: Difficult to load vs non-working cassettes

I'm no audio expert but I have a suggestion. Is there a way you can use a PC and capture the output and convert it to a wav format and post it? I'm sure some of the gurus here could then figure out a solution. I used Audicity when I did just the opposite (digital to audio) to compare my output to an...
by blittled
Tue Jul 25, 2017 6:03 pm
Forum: Development
Topic: Any info on ZX81 Serial Ports using the SIO chip?
Replies: 11
Views: 541

Re: Any info on ZX81 Serial Ports using the SIO chip?

Thanks siggi for mentioning the CTC. I was about to toss the whole idea out since I only had a 2.457MHz oscillator for the SIO clock so I could do only 38400 baud and I need 9600 as well. Do you have a schematic of the board so I can see how the CTC and SIO are interfaced?
by blittled
Mon Jul 24, 2017 11:20 pm
Forum: Development
Topic: Any info on ZX81 Serial Ports using the SIO chip?
Replies: 11
Views: 541

Re: Any info on ZX81 Serial Ports using the SIO chip?

Thanks for all the info :D I found the first link informative, especially the post about the board that uses an Atmega IC. That one is similar to my idea of using a Microchip PIC IC. The advantage to using a microcontroller is that you could easily make it read an I/O port and convert to Serial, I2C...
by blittled
Sun Jul 23, 2017 3:44 am
Forum: Development
Topic: Any info on ZX81 Serial Ports using the SIO chip?
Replies: 11
Views: 541

Any info on ZX81 Serial Ports using the SIO chip?

I have a plethora of ttl serial boards such as a Text to Speech module, ESP8266, Bluetooth, Arduino, PIC, Propeller and the Raspberry Pi and thought it would be fun to interface them with the ZX81. I realize wilf has a 8251 based board but I don't have that chip and I want to use parts I have. I do ...
by blittled
Thu May 18, 2017 2:42 pm
Forum: Welcome Area
Topic: Hi ZX Community
Replies: 14
Views: 569

Re: Hi ZX Community

Andrew,

Great story! :D I too attribute the ZX81 in getting me a job requiring Z80 Assembly. I bet many of the forum members have had life changing moments thanks to this little "doorstop" ;)
by blittled
Tue May 02, 2017 3:05 am
Forum: Development
Topic: ZXblast - ZX81 memory extension plus USB
Replies: 197
Views: 9570

Re: ZXblast - ZX81 memory extension plus USB

Can the SST39SF040 be programmed with a PICKIT 2 or 3? I have both. Also do I still need to get the CLPD reprogrammed if I flash the SST39SF040? I was having the same issue mrtinb trying to do the update with ZXMUPD21.ROM. I tried 2 reformatted usb sticks on a TS1000 and a ZX81 and couldn't get the ...
by blittled
Sat Apr 15, 2017 1:59 am
Forum: SALES
Topic: ZX81CCP
Replies: 87
Views: 7306

Re: ZX81CCP

What size Phillip Screw driver is used on the pots. Is it a 0#, 00#, 1#,etc? I need to make an adjustment and all my small screwdrivers won't work well.
by blittled
Thu Apr 13, 2017 6:20 pm
Forum: Hardware
Topic: Putting a ZX81 onto a CPLD
Replies: 59
Views: 2317

Re: Putting a ZX81 onto a CPLD

I'd be interested in the
8255, 8251, AY-3-8910 and SN76489 chips.