Z80CPM vs Subnet
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Z80CPM
Experience the classic CP/M operating system on your iOS or Mac device with a full Z80 processor emulator. Run authentic CP/M software, including operating systems, word processors, programming languages, and text adventures. Works offline with support for multiple disk images.
- Full Z80 emulation
- VT100 terminal support
- Multiple disk image mounting
- Offline functionality
- Native Mac support
- Downloadable CP/M disk images
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RomWBW CP/M brings the classic CP/M operating system to your iPhone, iPad, and Mac with a full Z80 processor emulator. FEATURES • Full Z80 Emulation - Accurate instruction emulation runs authentic CP/M software • VT100 Terminal - ANSI escape sequence support for text adventures and productivity apps • Multiple Disk Support - Mount up to 4 disk images simultaneously • Download Disk Images - Fetch CP/M disk images directly from the RomWBW project • Works Offline - Downloaded disk images are stored locally • Native Mac Support - Runs natively on macOS via Mac Catalyst CLASSIC SOFTWARE Run the software that defined personal computing: • Operating Systems: CP/M 2.2, CP/M 3, ZSDOS, NZCOM, ZPM3 • Word Processing: WordStar • Programming: Turbo Pascal, Microsoft BASIC • Text Adventures: Zork, Adventure, Hitchhiker's Guide to the Galaxy • Databases: dBASE II • And thousands more CP/M programs GETTING STARTED 1. Open Settings and download a disk image (CP/M 2.2 recommended) 2. Select the disk image for Unit 0 3. Press Play to start the emulator 4. Press 0 at the boot menu to boot from disk BUILT ON ROMWBW This emulator is built on the RomWBW HBIOS platform, the same firmware used by real retro Z80 hardware projects. Disk images are downloaded from the official RomWBW project and include freely distributable CP/M software. TECHNICAL DETAILS • 80x25 character terminal display • hd1k disk format (8MB per slice, 64MB per disk) • Hardware keyboard support • Portrait and landscape orientation Perfect for retrocomputing enthusiasts, computer history education, or anyone who wants to experience the operating system that launched the personal computer revolution.
Subnet
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Subnet Calculator is a clean, professional networking tool for network engineers, sysadmins, CCNA/CCNP students and developers. Enter an IP address and a prefix (or CIDR) and instantly get every subnet detail you need. IPv4 CALCULATIONS • Network and broadcast addresses • Usable host range and host count • Subnet mask, wildcard (inverse) mask, hex mask • Address class (A/B/C/D/E) and category (private / public / loopback / link-local / multicast …) • Binary view with the network and host portions colour-coded • Convert freely between mask and CIDR prefix • Correct handling of /31 (point-to-point) and /32 (single host) IPv6 CALCULATIONS • Address compression (::) and full expansion • Address type detection (global unicast / link-local / unique local / multicast …) • Network prefix, first and last address • Total address count (shown as a power of two and exact value), number of /64 subnets SUBNETTING • Equal split: divide a network by a new prefix and list every subnet • VLSM: allocate the right-sized subnet for each host requirement automatically WHY YOU'LL LIKE IT • 100% offline — no network access, no data collected, full privacy • Tap any result to copy it • Dark mode, universal for iPhone and iPad • English & Chinese, follows your system language • Clean interface, no ads Whether you're planning a network, studying for a certification, or troubleshooting on the job, this tool gets your subnet math done fast and accurately.
Screenshots
Verdict
The clearest difference is price: Z80CPM at Free against Subnet's $0.99. Z80CPM also leads on device support (4 vs 2). On ads, in-app purchases and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Z80CPM is free to download; Subnet costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
| Parameter | Z80CPM | Subnet |
|---|---|---|
| Price | Free — better | $0.99 |
| Rating | 5.0 (2 ratings) — better | — |
| Number of ratings | 2 — better | — |
| Update frequency | Every 10 days | — |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 1 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Aaron Wohl | 敬东 孙 |
In-app purchases
Z80CPM
No in-app purchases
Subnet
No in-app purchases









