Two 6502 System

codewar65 · Post by **codewar65** » Sat Aug 14, 2021 5:18 am

47 minutes ago, Scott Robison said:

It's good that you have an actual use for it, and nothing wrong with dumb terminals. In my case it was just a solution in search of a problem. ?

'Dumb' terminal is a term, for a terminal. Some weren't so dumb. ? I am just looking to offload cycles onto another processor with dedicated capabilities, like how C64's 'talked' to disc drives with their own 6502s.

Scott Robison · Post by **Scott Robison** » Sat Aug 14, 2021 5:38 am

Right, I remember dumb terminals. My first programming class in college was FORTRAN 77 which was hosted on one campus mainframe and we accessed it via 3270-style terminals. Later I worked for a company that put terminal emulation software in first responder vehicles so they could access the same systems they'd access from the office. I'm sure by now it's been replaced with web based terminal emulation, though given how slow government can be at times to change, who knows. It has been probably 18 years since I last had a clue about what that company was doing.

BruceMcF · Post by **BruceMcF** » Sat Aug 14, 2021 9:22 am

3 hours ago, Scott Robison said:

Right, I remember dumb terminals. My first programming class in college was FORTRAN 77 which was hosted on one campus mainframe and we accessed it via 3270-style terminals. Later I worked for a company that put terminal emulation software in first responder vehicles so they could access the same systems they'd access from the office. I'm sure by now it's been replaced with web based terminal emulation, though given how slow government can be at times to change, who knows. It has been probably 18 years since I last had a clue about what that company was doing.

Yes, when I was a Junior, the Freshmen got to use terminals for Fortran 77 class instead of having to use punch cards. I was so jealous.

Scott Robison · Post by **Scott Robison** » Sat Aug 14, 2021 4:21 pm

7 hours ago, BruceMcF said:

Yes, when I was a Junior, the Freshmen got to use terminals for Fortran 77 class instead of having to use punch cards. I was so jealous.

I missed the punched card era by just a few years. I never had to use them (or paper tape). However, I saw plenty of them. The professor of that FORTRAN class had a ton of punch cards, some unused, some punched. He would have several on him at all times and would use them for note cards.

One reason why I got the TA job a couple years later: I found a bug in the mainframe compiler. Of course, it seems every student says that at some point in time, but I really did. He would not believe it until I was able to demonstrate that my program worked on the PC version of the compiler from the same vendor (WATFOR77) and only had problems on the mainframe. ?

Fenner Machine · Post by **Fenner Machine** » Sun Aug 22, 2021 9:37 pm

What if you could connect an X8 to an expansion slot on the X16?

Scott Robison · Post by **Scott Robison** » Sun Aug 22, 2021 9:39 pm

You need available IO lines in order for the two to communicate. I don't know exactly what hardware the X8 will be based on, but I doubt it will have sufficient IO lines to accomplish this task.

BruceMcF · Post by **BruceMcF** » Mon Aug 23, 2021 2:56 am

5 hours ago, Scott Robison said:

You need available IO lines in order for the two to communicate. I don't know exactly what hardware the X8 will be based on, but I doubt it will have sufficient IO lines to accomplish this task.

Well, we don't have many details of the X8, but if it allows an RTC, then it may have an I2C channel for communication. If that is brought out on the board to a pin header, then a two wire ribbon cable could connect it to the CX16 I2C.

But part of the cost savings compared to the CX16e is that with the 128K SPRAM all of the RAM it uses, it doesn't have to bring data and address buses out.

And we know that when the Vera FPGA moved from 8 registers addressed on the system bus to 32, which is two more pins, they also pulled out the serial port, for lack of pins, So if the LX8 is allocating pins to the USB, and to things like supporting an I2C bus for a RTC, then they wouldn't have the pins to plug it into a CX16p slot.

BruceMcF · Post by **BruceMcF** » Mon Aug 23, 2021 3:39 am

6 hours ago, Fenner Machine said:

What if you could connect an X8 to an expansion slot on the X16?

What if pigs could fly? Would we need to invest in stronger umbrellas?

"An X8 that could be tweaked to add an expansion slot" is the CX16e, it's not the X8. It's always easy to come up with a "better" design that doesn't "suffer from the limits" of a particular design ... if you free yourself from having to live within the real world constraints that led to those limits.

TomXP411 · Post by **TomXP411** » Mon Aug 23, 2021 4:22 am

39 minutes ago, BruceMcF said:

What if pigs could fly? Would we need to invest in stronger umbrellas?

"An X8 that could be tweaked to add an expansion slot" is the CX16e, it's not the X8. It's always easy to come up with a "better" design that doesn't "suffer from the limits" of a particular design ... if you free yourself from having to live within the real world constraints that led to those limits.

I don't even care about an expansion slot. I just want a enough of GPIO that we can have a serial port. Give me a UART and I can talk to the world.

Scott Robison · Post by **Scott Robison** » Mon Aug 23, 2021 4:26 am

2 minutes ago, TomXP411 said:

I don't even care about an expansion slot. I just want a enough of GPIO that we can have a serial port. Give me a UART and I can talk to the world.

Wouldn't you need a WART to talk to the world? I guess the world is part of the "universal" charter of the UART. #insertdadjokegroanhere