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#G540 programmer driver drivers
#G540 programmer driver update
#G540 programmer driver code

Unix and other Unix-like systems such as Linux and OS X use CUPS (short for Common Unix Printing System), a modular printing system for Unix-like computer operating systems, which allows a computer to act as a print server.

#G540 programmer driver drivers

Printer drivers in different operating systems Unix and Unix-like

2.2 Converters to device-specific format.

1 Printer drivers in different operating systems.

I haven't considered it much beyond that, so it's currently just an idea (hope?) that I'm hanging onto right now.įile comment: Build 4 w/ 65816 and 512k memory, running 6502 Forth in emulation modeīuild4_exram_working. I think I was hoping to rely on one of the busted myths form your 65816 Facts and Myths post, that the 65816 banks could be addressed as a whole. When cross-bank accesses become necessary, the and ,Y addressing modes are your friend. You should arrange the memory map to minimize cross-bank accesses as much as possible. While use of a PLD in place of discrete logic does confer flexibility, as well as greatly reduce chip count, the 816 itself knows nothing about all that. Honestly, I have on my to do list some of your posts on the subject, so I have a lot more learning to do. At this point even three banks of memory seems like a luxury. I figured I'd use another address mode for banks above that, but I'll admit I haven't given it much thought. But AFAIK the penalty only applies once, even in the case of a R-M-W And can you supply a reference for your statement that long accesses using R-M-W instructions will incur multiple clock cycle penalties per instruction? Long address modes do mean the instruction will include a three-byte address, and certainly it costs an extra cycle to fetch that additional byte.

#G540 programmer driver update

I'm drawing a blank on your suggestion to "split your ISR between bank $00 and the I/O bank and JML to the rest of the ISR." Like an interrupt, JML fails to update DBR. That's why I say having I/O appear in Bank $00 isn't a very useful shortcut for avoiding the penalty

#G540 programmer driver code

Or, the DBR update becomes unnecessary if we make a rule that the foreground code must disable interrupts anytime it wants to use a DBR value other than $00, but this is an unappealing compromise. So, if the ISR explicitly updates DBR then the penalty can be avoided. The Data Bank Register DBR does not get pushed to stack (booboo edited as per your correction, tmr4 - thx), and - more to the point - neither is a new value written to it - DBR remains unchanged from the value it had prior to the interrupt. The Program Bank Register PBR gets pushed to stack when an interrupt is recognized, and also a new value (ie, $00) written to it. But I'm doubtful that having I/O appear in Bank $00 is of much use for avoiding that penalty. It's true that long accesses incur a penalty, and of course we'd prefer to avoid that. That will negatively affect performance because inter-bank accesses require one more clock cycle per access than do accesses using 16-bit (absolute) addressing. You would be forced to use long addressing for all I/O accesses within the interrupt handler (ISR). Either way, I recommend you give this more thought before committing to a particular memory map.

However, since the ISR's preamble must be in bank $00, you may find firmware development to be too convoluted. The single long jump would be less “expensive” than repeated long accesses. The fewer addressing shenanigans required to access I/O and runtime data structures, the more performance you will achieve at any given Ø2 rate.Īlternatively, you could split your ISR between bank $00 and the I/O bank and JML to the rest of the ISR. In particular, long accesses using R-M-W instructions will incur multiple clock cycle “penalties” per instruction.Īs described here, succinctness is a primary goal in ISRs-time spent processing IRQs is time not available to process foreground tasks. Assuming I/O is interrupt-driven, you would be forced to use long addressing for all I/O accesses within the interrupt handler ( ISR). You should be aware that placing I/O hardware at an extended address as you are doing will probably complicate your firmware in several ways. Also, could you please post the entire source code, not just fragments? What type of PLD is this you are programming? That matters if we are going to help you figure out your problem. I'm trying to code the following memory map for the PLD address decoder for my 65816: