Despite the nominally high clock rate, this caused the computer to run slower than several of its competitors and resulted in an effective clock rate of 6MHz.
EXTERNAL RAM FOR MAC CODE
Such an arrangement reduced the overall performance of the CPU as much as 35% for most code as the display logic often blocked the CPU's access to RAM. The 68000 and video controller took turns accessing DRAM every four CPU cycles during display of the frame buffer, while the 68000 had unrestricted access to DRAM during vertical and horizontal blanking intervals. The RAM in the Macintosh consisted of sixteen 64k×1 DRAMs. Unlike the Apple II, no source code listings of the Macintosh system ROMs were offered. The boot procedure and some operating system routines were contained in an additional 64kB ROM chip.
The heart of the computer was a Motorola 68000 microprocessor running at 7.8336MHz, connected to 128kB RAM shared by the processor and the display controller.
A handle built into the top of the case made it easier for the computer to be lifted and carried. It played a pivotal role in establishing desktop publishing as a general office function. Its beige case consisted of a 9 in (23 cm) CRT monitor and came with a keyboard and mouse. The Macintosh 128K, originally released as the Apple Macintosh, is the original Apple Macintosh personal computer. Motorola 68000 7.8336 MHz (6 MHz effectively) Īpple Macintosh 128K in trilogy «Back to the Future»
EXTERNAL RAM FOR MAC MAC
Is your Mac running normally after using these steps? Share with us in a comment.January 24, 1984 37 years ago ( ) If your Mac has been misbehaving, resetting the PRAM or SMC (or both) will get it back to operating as you expect it to. These tests contain a suite of diagnostics that test your Mac for hardware issues, suggest solutions, and help you contact Apple Support for further assistance. If a PRAM/NVRAM or SMC reset doesn’t help, try using the Apple Diagnostics or Apple Hardware Test (for Macs introduced before June 2013). Wait another 5 seconds and then press the Power button to turn on the computer. Press and hold the Power button for 5 seconds, reinstall the battery, and then press the Power button to turn on the Mac.įor desktop Mac computers without the Apple T2 Security Chip, shut down the Mac, unplug the power cable and wait 15 seconds before plugging the cable back in. If you have a Mac notebook with a removable battery, shut down the Mac and remove the battery. Release the four keys after 10 seconds and press the Power button to turn on the Mac.Release the keys after 20 or so seconds and your Mac will appear to restart. To reset PRAM/NVRAM, shut down your Mac, power it on and press and hold the Option, Command, P and R keys together at the same time.Resetting the PRAM/NVRAM on your Mac sets the hard drive as the startup disk and restores the default hardware settings. Plus, you need to disconnect all speakers, dongles, drives, external displays, and keyboards so that nothing will interfere with the resetting process. You can back them up to an external drive or a USB key. Resetting your Mac should be a last resort when troubleshooting options such as rebooting and other tricks to speed up a slow computer fail.īefore you can reset the PRAM and SMC on your Mac, have a recent backup of all your critical stuff. Bouncing Dock icons keep bouncing without opening the related apps.Power indicator not displaying or displaying incorrectly.Mac doesn’t respond properly when you open or close the lid.Mac runs unusually slowly even with little CPU usage.Battery doesn’t appear to be charging properly.Keyboard backlight, battery indicator light, display backlight, and status indicator lights behave incorrectly.Such issues include but aren’t limited to:
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