always black lines in between) but usually only gave a rough impression of different coloured areas. This worked fine on pictures with sharp contrasts (i.e.
#HERCULES EMULATOR FASTCOPY UTILITY SOFTWARE#
Depending on the software this was compensated by replacing the colours by fixed patterns.
The other big drawbacks were ugly pictures due to the fact that converting a colour picture to monochrome always loses information. As a result, only a part of the screen was used (or parts of the picture cropped) and colour information was dropped. Weird Screen Format - Again due to the complexity of conversion, some emulators offered modes where less complex calculations were used by restricting the display area and colour resolution. Again sometimes to an unplayable low when it came to (re)action games. Doing the conversion only every second, third or fourth frame, reducing the effective frame rate. While not much of an issue for round based or adventure games, it was real hurdle for real time/action games.Īs well as Lag - One way to reduce the impact on the game performance was to skip frames. Most notable Speed - Games got slowed down. While not an issue with later PCs, it was a deal breaker early on. To make it happen, the emulator had to steal the cycles to do so from the game. Most are related to the fact that the conversion of colour and resolution was done in software. Accolade's well known Test Drive for example. In fact, some games even skipped programming a Hercules mode by using a built-in (third party) CGA emulation. For games with direct control of the CGA's registers, patches were sometimes available. This was also supported by the fact that while many programs did direct screen updates, configuration was mostly done via BIOS calls, which could also be intercepted by the emulation and handled accordingly. On fast machines that could happen for every frame. A timer controlled interrupt would now read the virtual CGA buffer at B8000h and transform its content into the real Hercules buffer at B0000h. Programs assuming a CGA (and direct screen access) would go ahead and paint their output into this memory instead.
#HERCULES EMULATOR FASTCOPY UTILITY FULL#
Unlike the MDA, the Hercules card did offer a full graphics mode of 720x348 (*3,4), which occupied 32 KiB Memory, thus offering up to two pages.ĬGA emulations used the fact that the second 32 KiB were not only free (when only the first graphics page was used) but also that memory could be located where the CGA's 16 KiB are, at B8000h.BBFFFh. In fact, so compatible that the PCs BIOS did recognize and use it as MDA (with 4 KiB Memory). By default the Hercules was 100% compatible. To avoid conflicts with a CGA in the same system the upper 32 KiB were by default disabled.
The Hercules card in contrast had 64 KiB of memory (*2), starting at B0000h. The original MDPA (*1) had (only) 4 KiB of memory mapped at B0000h, while the CGA had 16 KiB of Memory at B8000h.
They were based on the ability of the Hercules card use the CGA's memory space.
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