On 01/15/2017 09:37 AM, Glen Slick wrote:
> In the EPROM binary dump you posted I see code that is doing IN and > OUT accesses to the following port locations... I've seen that technique used to address a device, such as off-chip EEPROM--basically, rather than employ a separate latch for the address or map the device into memory space, a block of I/O addresses are used to directly access the device. It seems wasteful--and, as the code points out, rather inflexible, as the 8085 only has the immediate-operand IN and OUT instructions, but hey, it saves a couple of chips. So, the first thing that I'd look for is what devices on the board can be accessed in this fashion. --Chuck
