Search found 2294 matches

by Dave
Tue May 21, 2019 6:05 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 35
Views: 985

Re: Asymmetric multiprocessing...

But that can be better done with fast SERial 68681 (one of the reasons why I'm doing it); 31250 MIDI option with opto-isolators along with full SER. Take a look at the NXP SCC2691. It has an auto-repeater feature which make the in/thru/out implementation not require any extra repeater hardware. App...
by Dave
Tue May 21, 2019 5:09 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 35
Views: 985

Re: Asymmetric multiprocessing...

But that can be better done with fast SERial 68681 (one of the reasons why I'm doing it); 31250 MIDI option with opto-isolators along with full SER. You'd have to change the crystal to get the right baud rate out of the 68681, so you would need to use a separate 68681 for MIDI and for serial. If th...
by Dave
Tue May 21, 2019 12:04 am
Forum: General QL Chat
Topic: Internet and the QL
Replies: 38
Views: 1567

Re: Internet and the QL

But it does not contain the QL-side email client, which is where the procedures of communication with the server need to be handled, and where the ESP32 functions would need to be attached. The QL-side software for that does not automatically exist, just because there is a piece of ESP32 hardware. ...
by Dave
Mon May 20, 2019 2:34 pm
Forum: General QL Chat
Topic: Internet and the QL
Replies: 38
Views: 1567

Re: Internet and the QL

I wonder if a pragmatic approach, like finding or hosting classic email servers, could help without "outsourcing" encryption to a non-native CPU. (By the way, I'm not sure that an encryption engine outside the QL would automatically lead to the development of an email client which can han...
by Dave
Mon May 20, 2019 2:54 am
Forum: General QL Chat
Topic: Internet and the QL
Replies: 38
Views: 1567

Re: Internet and the QL

I find it exaggerated to say that TCP/IP is useless without encryption. It can still be used for LAN connections, internet connections from QL to QL, and many websites. From my experience with QLwIP I see the largest problem in the requirement of encryption for email server connections. (Which does...
by Dave
Sun May 19, 2019 8:30 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 35
Views: 985

Re: Asymmetric multiprocessing...

Derek_Stewart wrote:I have not checked them against the original, but they look about right.


So Dn -> ZAn and An -> ZDn? Why would they do that?
by Dave
Sun May 19, 2019 8:25 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 35
Views: 985

Re: Asymmetric multiprocessing...

....for a basic system you don’t need dual port RAM. One third party Z80 second processor system for the Acorn BBC B used two PIO chips back-back for processor to processor communications. In this case a 6522 VIA for the 6502 and a 8255A for the Z80A. Nothing *needs* dual port RAM. But: If I put a ...
by Dave
Sat May 18, 2019 9:18 pm
Forum: General QL Chat
Topic: Internet and the QL
Replies: 38
Views: 1567

Re: Internet and the QL

A real TCP/IP card for the QL will be more interesting for me: It can be a new way for write new software that can connect directly on internet (IRC, client email, browsers, etc...). A real TCP/IP card is only useful if we have access to an encryption engine. It would take a QL several days to encr...
by Dave
Sat May 18, 2019 5:26 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 35
Views: 985

Re: Asymmetric multiprocessing...

What about a graphics processor. The QL operating system just tells the second processor to display a character at a particular position, or draw a line between two points. Then gets on with something else, while the second processor gets on with it. The QL side would not get bogged down dealing wi...
by Dave
Sat May 18, 2019 5:22 pm
Forum: Hardware
Topic: Asymmetric multiprocessing...
Replies: 35
Views: 985

Re: Asymmetric multiprocessing...

But looking at the Issue 8 discussion, Rom Port is being removed. Issue 8 is definitely retaining the ROM port. What we're doing is ending the motherboard between the ROM port and joystick port. An extender will implement the ROM port, and can either be used or - if you're not using the ROM port - ...